Purpose: Since 2000, the Korea University Medical College has conducted Comprehensive Basic Medical Sciences Examination as a summative test. Summative assessment must be dependable in that it meets the highest standards of reliability and validity. The purpose of this study were to examine the validity and reliability of Comprehensive Basic Medical Sciences Examination and to improve the quality of the examination. Methods: The subject of this study was the examination materials and scores of the test. We conducted exploratory factor analysis to testify validity. Cronbach α coefficient was used to examine the reliability. Results: Only one factor was extracted from exploratory factor analysis. Its eigen value was 4.61 and it explained 65.93% of total variance. We could infer the extracted factor as an ability of basic medical sciences knowledge. The reliability coefficient of the test was ranged from 0.45 to 0.74. Of the total 335 item, overall acceptable items were 206 (58.0%); the range of difficulty was 0.21～1.00 and discriminative indices were higher than 0.20. Conclusion: We confirmed the Comprehensive Basic Medical Sciences Examination in 2000 met the relative highest standards of reliability and validity. Item analysis could be of help to improve the quality of examination