Objectives : The biosafety level (BSL) practiced in microbiology laboratories in Korea according to the laboratory biosafety manual published by the World Health Organization (WHO) was evaluated using the data obtained by a survey. Methods : Under the advise of Clinical Laboratory Physicians, 144 types of microorganisms were screened based on the guidelines of biosafety in microbiological and biomedical laboratories published by the US Center for Disease Control and Prevention and classified into 1-4 risk groups. A questionnaire containing 21 questions in 5 areas was developed using the biosafety manual by published WHO. Of the 1,876 different organizations sent the survey, 563 responded to the survey (response rate: 30.0%). The species of microoganisms handled by as well as the biosafety level in microbiology laboratories were analyzed. Results : There were 123 species of microorganisms handled in microbiology labs in Korea. The BSL required in 512 microbiology labs was answered by the survey responders as the first grade in 33 labs (6.4%), 2nd in 437 (85.4%), 3rd in 42 (8.2%), and 4th in none. The average number of items satisfied was 12.2, showing only a 57.9% satisfactory rate and normal distribution. Conclusions : The state of overall observance of BSL in most microbiology labs of Korea was evaluated as lagging compared with the standard set up by WHO. Therefore, the Korean government need to produce and distribute a biosafety manual in microbiology laboratories and make efforts to prevent this threat through measures such as training in biosafety in microbiology labs.