The Afghanistan Ministry of Interior (MoI) conducted nationwide urinary drug screening of Afghanistan National Police (ANP) officers for tetrahydrocannabinol, opiates, d-Methamphetamine, and benzoylecgonine -- commonly referred to as cocaine -- between November 2009 and July 2010. The testing was accomplished in concert with the MoI's Personnel Asset Inventory. ANP members used standardized kits from the United States. Of the 100,518 ANP tested, 9% (9,034) were positive for at least one of the target drugs: 80.5% (7,269) screened positive for tetrahydrocannabinol, 15.5% (1,399) for opiates, 2.5% (226) for d-Methamphetamine, and 1.5% (140) for benzoylecgonine. The drug-positive rate for ANP decreased from a high of 21% in November 2009 to 4% in June 2010 (p < 0.001), suggesting that the newly established MoI antidrug policy and drug screening may have discouraged drug use among ANP officers. The MoI needs to continue to educate its officers on the antidrug policy, improve drug testing procedures, and take appropriate disciplinary action against offenders in order to continue to improve the effectiveness of its nascent antidrug actions.