Virtually all professional and amateur sporting organizations forbid the use of androgenic anabolic steroids (AAS). The International Olympic Committee, United States Olympic Committee, and more recently the National Collegiate Athletic Association enforce the regulations by conducting urine testing. Over the past 3 years we have conducted about 8000 tests for AAS in urine and discovered several hundred positive cases. AAS when present in urine can be detected by screening and confirmatory tests using gas chromatography-mass spectrometry.