This little program, compiled on VC++ 8.0 leaks memory, apparently. #define BOOST_AUTO_TEST_MAIN #include <boost/test/auto_unit_test.hpp> #include <boost/thread/thread.hpp> void f() {} BOOST_AUTO_TEST_CASE(threads_leak) { boost::thread thrd(&f); thrd.join(); } Output: Running 1 test case... *** No errors detected Detected memory leaks! Dumping objects -> {218} normal block at 0x00357458, 24 bytes long. Data: < 9 > 80 39 15 00 FF FF FF FF 00 00 00 00 00 00 00 00 {217} normal block at 0x00357398, 8 bytes long. Data: <Xt5 > 58 74 35 00 01 CD CD CD Object dump complete. Versions: Boost-1.33.1 VC++8.0 (debug mode) Windows XP extra lib: libboost_unit_test_framework-vc80-mt-gd.lib (not auto-linked) Can anyone using VC++ 8.0 and the release version of Boost confirm this? With Google, I found some past references to Boost.Thread leaking memory.