Cambodia's Ministry of Health and the Department of Drugs and Food have been actively working to reduce the amount of poor quality medicines circulating in the pharmaceutical sector since fake mefloquine and artesunate were first found in 1998. From 2005-2012, legal private sector facilities and illegal outlets in twelve Cambodian provinces were targeted for routine surveillance of medicine quality through sample collection and testing of various anti-infective medicines, the majority of which were anti-malarials and anti-biotics. The Medicine Quality Monitoring program samples from the field were analyzed through a three level approach including field and advanced laboratory testing. 4,381 medicines were collected and tested from 2005-2012; 106 have failed quality testing resulting in an overall failure rate of 2.4%. 28 of the failed samples (26.4%) were counterfeit. The most commonly found counterfeit medicines were chloroquine, artesunate, mefloquine, ampicillin and penicillin. Cambodia has closed over 99% of illegal pharmacy outlets through the Inter-Ministerial Committee to Fight against Counterfeit & Substandard Medicines (IMC) by the end of November 2011. In the past, a lack of resources as well as coordination among the various ministries was identified as a major barrier in combating the presence of poor quality medicines. With financial support from USAID, PMI, and other donors, paired with the technical support from the U.S. Pharmacopeial Convention Promoting the Quality of Medicines program, the IMC developed an action plan to significantly reduce the number of substandard and counterfeit medicines. Based on the data shown, the plan has been successful in reducing the failure rates of samples collected in Cambodia from a high of 7.4% in 2006 to a low of 0.7% in 2011. Continued efforts to monitor and actively ensure the quality of medicines in Cambodia will be required to maintain these low rates; sustainability of these efforts is critical.