N-Nitrosodimethylamine (NDMA) was determined in both domestic Korean and imported beers, from the Netherlands, USA, Japan, Belgium and Germany. Among the 8 kinds of Korean beers, 4 were contaminated with NDMA, and 4 were not. The average concentration of NDMA detected in Korean beers was 0.78 $mu extrm{g}$/kg and the maximum NDMA concentration was 5.73 $mu extrm{g}$/kg. NDMA was only detected in one imported beer, which had a concentration of 5.29 $mu extrm{g}$/kg. Assuming an average concentration of 0.78 $mu extrm{g}$/kg NDMA in Korean domestic beer, the average daily intake of NDMA through domestic beer consumption by a typical Korean is approximately 0.58 $mu extrm{g}$/person/day.