European Medicines Agency withdrew valsartan from European market in July 2018 because it was contaminated with carcinogen, N-nitrosodimethylamine (NDMA) and N-nitrosodiethylamine (NDEA). Medicines and Healthcare Products Regulatory Agency also found the same contamination and withdrew it from England market. US Food and Drug Administration followed the action after confirming its contamination. Ministry of Food and Drug Safety (MFDS) conducted testing all the valsartans at Korean market and withdrew some of them from market after confirming the contamination with NDMA. MFDS provided the pharmaceutical companies and laboratory institutions with the manual for testing both NDMA and NDEA and educated relevant personnels. MFDS also evaluated the health impact of the contaminated valsartan on the hypertensive patients who took the valsartan, which was shown to be very low risk of additional cancer incidence. MFDS pronounced strengthening of the safety management for the raw materials of the medicines. For guaranteeing the safety of medicines, more comprehensive drug safety management system from developing new drugs to consuming the medicines should be established. For achieving such a goal, active participation of all the stakeholders of the medicines including governmental agencies including MFDS and Ministry of Health and Welfare, the National Assembly, healthcare professionals, pharmaceutical companies, mass media, and general population including patients should be needed.