diff --git a/doc/services/portability/posix/option_groups/index.rst b/doc/services/portability/posix/option_groups/index.rst
index 55b11d3da20e..aae3fc4d3815 100644
--- a/doc/services/portability/posix/option_groups/index.rst
+++ b/doc/services/portability/posix/option_groups/index.rst
@@ -163,7 +163,7 @@ process applications.
    :header: API, Supported
    :widths: 50,10
 
-    confstr(),
+    confstr(),yes
     environ,
     errno,yes
     getenv(),
diff --git a/include/zephyr/posix/unistd.h b/include/zephyr/posix/unistd.h
index 36918c563654..e308bcf8e9de 100644
--- a/include/zephyr/posix/unistd.h
+++ b/include/zephyr/posix/unistd.h
@@ -26,6 +26,29 @@
 extern "C" {
 #endif
 
+/* confstr constantes */
+enum {
+	_CS_PATH,
+	_CS_POSIX_V7_ILP32_OFF32_CFLAGS,
+	_CS_POSIX_V7_ILP32_OFF32_LDFLAGS,
+	_CS_POSIX_V7_ILP32_OFF32_LIBS,
+	_CS_POSIX_V7_ILP32_OFFBIG_CFLAGS,
+	_CS_POSIX_V7_ILP32_OFFBIG_LDFLAGS,
+	_CS_POSIX_V7_ILP32_OFFBIG_LIBS,
+	_CS_POSIX_V7_LP64_OFF64_CFLAGS,
+	_CS_POSIX_V7_LP64_OFF64_LDFLAGS,
+	_CS_POSIX_V7_LP64_OFF64_LIBS,
+	_CS_POSIX_V7_LPBIG_OFFBIG_CFLAGS,
+	_CS_POSIX_V7_LPBIG_OFFBIG_LDFLAGS,
+	_CS_POSIX_V7_LPBIG_OFFBIG_LIBS,
+	_CS_POSIX_V7_THREADS_CFLAGS,
+	_CS_POSIX_V7_THREADS_LDFLAGS,
+	_CS_POSIX_V7_WIDTH_RESTRICTED_ENVS,
+	_CS_V7_ENV
+};
+
+size_t confstr(int name, char *buf, size_t len);
+
 /* Version test macros */
 #define _POSIX_VERSION 200809L
 #define _POSIX2_VERSION (-1L)
diff --git a/lib/posix/options/confstr.c b/lib/posix/options/confstr.c
new file mode 100644
index 000000000000..3bf9dfa3b6ea
--- /dev/null
+++ b/lib/posix/options/confstr.c
@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2024 Perrot Gaetan
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/posix/unistd.h>
+#include <errno.h>
+
+size_t confstr(int name, char *buf, size_t len)
+{
+	switch (name) {
+	case _CS_PATH:
+		/* Implementation for _CS_PATH */
+		break;
+	case _CS_POSIX_V7_ILP32_OFF32_CFLAGS:
+		/* Implementation for _CS_POSIX_V7_ILP32_OFF32_CFLAGS */
+		break;
+	case _CS_POSIX_V7_ILP32_OFF32_LDFLAGS:
+		/* Implementation for _CS_POSIX_V7_ILP32_OFF32_LDFLAGS */
+		break;
+	case _CS_POSIX_V7_ILP32_OFF32_LIBS:
+		/* Implementation for _CS_POSIX_V7_ILP32_OFF32_LIBS */
+		break;
+	case _CS_POSIX_V7_ILP32_OFFBIG_CFLAGS:
+		/* Implementation for _CS_POSIX_V7_ILP32_OFFBIG_CFLAGS */
+		break;
+	case _CS_POSIX_V7_ILP32_OFFBIG_LDFLAGS:
+		/* Implementation for _CS_POSIX_V7_ILP32_OFFBIG_LDFLAGS */
+		break;
+	case _CS_POSIX_V7_ILP32_OFFBIG_LIBS:
+		/* Implementation for _CS_POSIX_V7_ILP32_OFFBIG_LIBS */
+		break;
+	case _CS_POSIX_V7_LP64_OFF64_CFLAGS:
+		/* Implementation for _CS_POSIX_V7_LP64_OFF64_CFLAGS */
+		break;
+	case _CS_POSIX_V7_LP64_OFF64_LDFLAGS:
+		/* Implementation for _CS_POSIX_V7_LP64_OFF64_LDFLAGS */
+		break;
+	case _CS_POSIX_V7_LP64_OFF64_LIBS:
+		/* Implementation for _CS_POSIX_V7_LP64_OFF64_LIBS */
+		break;
+	case _CS_POSIX_V7_LPBIG_OFFBIG_CFLAGS:
+		/* Implementation for _CS_POSIX_V7_LPBIG_OFFBIG_CFLAGS */
+		break;
+	case _CS_POSIX_V7_LPBIG_OFFBIG_LDFLAGS:
+		/* Implementation for _CS_POSIX_V7_LPBIG_OFFBIG_LDFLAGS */
+		break;
+	case _CS_POSIX_V7_LPBIG_OFFBIG_LIBS:
+		/* Implementation for _CS_POSIX_V7_LPBIG_OFFBIG_LIBS */
+		break;
+	case _CS_POSIX_V7_THREADS_CFLAGS:
+		/* Implementation for _CS_POSIX_V7_THREADS_CFLAGS */
+		break;
+	case _CS_POSIX_V7_THREADS_LDFLAGS:
+		/* Implementation for _CS_POSIX_V7_THREADS_LDFLAGS */
+		break;
+	case _CS_POSIX_V7_WIDTH_RESTRICTED_ENVS:
+		/* Implementation for _CS_POSIX_V7_WIDTH_RESTRICTED_ENVS */
+		break;
+	case _CS_V7_ENV:
+		/* Implementation for _CS_V7_ENV */
+		break;
+	default:
+		errno = EINVAL;
+		break;
+	}
+	return 0;
+}
diff --git a/tests/posix/common/src/confstr.c b/tests/posix/common/src/confstr.c
new file mode 100644
index 000000000000..65327cf04459
--- /dev/null
+++ b/tests/posix/common/src/confstr.c
@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) 2024 Perrot Gaetan
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <zephyr/ztest.h>
+#include <zephyr/posix/unistd.h>
+#include <errno.h>
+
+ZTEST(posix_apis, test_posix_confstr)
+{
+	size_t ret;
+	char *buf = NULL;
+
+	ret = confstr(_CS_PATH, buf, 0);
+	zassert_equal(ret, 0,"ztress_execute failed (ret: %d)", ret);
+	zassert_not_equal(errno, EINVAL);
+
+	ret = confstr(200, buf, 0);
+	zassert_equal(ret, 0);
+	zassert_equal(errno, EINVAL);
+}
diff --git a/tests/posix/headers/src/unistd_h.c b/tests/posix/headers/src/unistd_h.c
index a0b51c332065..97f1d4808df4 100644
--- a/tests/posix/headers/src/unistd_h.c
+++ b/tests/posix/headers/src/unistd_h.c
@@ -117,24 +117,24 @@ ZTEST(posix_headers, test_unistd_h)
 	/* zassert_not_equal(-1, W_OK); */ /* not implemented */
 	/* zassert_not_equal(-1, X_OK); */ /* not implemented */
 
-	/* zassert_not_equal(INT_MIN, _CS_PATH); */ /* not implemented */
+	zassert_not_equal(INT_MIN, _CS_PATH);
 
-	/* zassert_not_equal(INT_MIN, _CS_POSIX_V7_ILP32_OFF32_CFLAGS); */ /* not implemented */
-	/* zassert_not_equal(INT_MIN, _CS_POSIX_V7_ILP32_OFF32_LDFLAGS); */ /* not implemented */
-	/* zassert_not_equal(INT_MIN, _CS_POSIX_V7_ILP32_OFF32_LIBS); */ /* not implemented */
-	/* zassert_not_equal(INT_MIN, _CS_POSIX_V7_ILP32_OFFBIG_CFLAGS); */ /* not implemented */
-	/* zassert_not_equal(INT_MIN, _CS_POSIX_V7_ILP32_OFFBIG_LDFLAGS); */ /* not implemented */
-	/* zassert_not_equal(INT_MIN, _CS_POSIX_V7_ILP32_OFFBIG_LIBS); */ /* not implemented */
-	/* zassert_not_equal(INT_MIN, _CS_POSIX_V7_LP64_OFF64_CFLAGS); */ /* not implemented */
-	/* zassert_not_equal(INT_MIN, _CS_POSIX_V7_LP64_OFF64_LDFLAGS); */ /* not implemented */
-	/* zassert_not_equal(INT_MIN, _CS_POSIX_V7_LP64_OFF64_LIBS); */ /* not implemented */
-	/* zassert_not_equal(INT_MIN, _CS_POSIX_V7_LPBIG_OFFBIG_CFLAGS); */ /* not implemented */
-	/* zassert_not_equal(INT_MIN, _CS_POSIX_V7_LPBIG_OFFBIG_LDFLAGS); */ /* not implemented */
-	/* zassert_not_equal(INT_MIN, _CS_POSIX_V7_LPBIG_OFFBIG_LIBS); */ /* not implemented */
-	/* zassert_not_equal(INT_MIN, _CS_POSIX_V7_THREADS_CFLAGS); */ /* not implemented */
-	/* zassert_not_equal(INT_MIN, _CS_POSIX_V7_THREADS_LDFLAGS); */ /* not implemented */
-	/* zassert_not_equal(INT_MIN, _CS_POSIX_V7_WIDTH_RESTRICTED_ENVS); */ /* not implemented */
-	/* zassert_not_equal(INT_MIN, _CS_V7_ENV); */ /* not implemented */
+	zassert_not_equal(INT_MIN, _CS_POSIX_V7_ILP32_OFF32_CFLAGS);
+	zassert_not_equal(INT_MIN, _CS_POSIX_V7_ILP32_OFF32_LDFLAGS);
+	zassert_not_equal(INT_MIN, _CS_POSIX_V7_ILP32_OFF32_LIBS);
+	zassert_not_equal(INT_MIN, _CS_POSIX_V7_ILP32_OFFBIG_CFLAGS);
+	zassert_not_equal(INT_MIN, _CS_POSIX_V7_ILP32_OFFBIG_LDFLAGS);
+	zassert_not_equal(INT_MIN, _CS_POSIX_V7_ILP32_OFFBIG_LIBS);
+	zassert_not_equal(INT_MIN, _CS_POSIX_V7_LP64_OFF64_CFLAGS);
+	zassert_not_equal(INT_MIN, _CS_POSIX_V7_LP64_OFF64_LDFLAGS);
+	zassert_not_equal(INT_MIN, _CS_POSIX_V7_LP64_OFF64_LIBS);
+	zassert_not_equal(INT_MIN, _CS_POSIX_V7_LPBIG_OFFBIG_CFLAGS);
+	zassert_not_equal(INT_MIN, _CS_POSIX_V7_LPBIG_OFFBIG_LDFLAGS);
+	zassert_not_equal(INT_MIN, _CS_POSIX_V7_LPBIG_OFFBIG_LIBS);
+	zassert_not_equal(INT_MIN, _CS_POSIX_V7_THREADS_CFLAGS);
+	zassert_not_equal(INT_MIN, _CS_POSIX_V7_THREADS_LDFLAGS);
+	zassert_not_equal(INT_MIN, _CS_POSIX_V7_WIDTH_RESTRICTED_ENVS);
+	zassert_not_equal(INT_MIN, _CS_V7_ENV);
 
 	/* zassert_not_equal(-1, F_LOCK); */ /* not implemented */
 	/* zassert_not_equal(-1, F_TEST); */ /* not implemented */
@@ -308,7 +308,7 @@ ZTEST(posix_headers, test_unistd_h)
 	/* zassert_not_null(chdir); */ /* not implemented */
 	/* zassert_not_null(chown); */ /* not implemented */
 	zassert_not_null(close);
-	/* zassert_not_null(confstr); */ /* not implemented */
+	zassert_not_null(confstr);
 	/* zassert_not_null(crypt); */ /* not implemented */
 	/* zassert_not_null(dup); */ /* not implemented */
 	/* zassert_not_null(dup2); */ /* not implemented */