We tried to develop Korean computerized neurobehavioral tests to promote neurobehavioral research and screening in occupational setting in Korea. This program was designated Neurobehavioral Tests for Occupational Screening (NTOS). NTOS consisted of 3 test items, choice reaction time (2 choice and 4 choice), simple reaction time (visual and auditory stimulus), finger tapping test (both hands). NTOS was administered to 120 students of medical school and to evaluate applicability. The results of reaction time tests was positively skewed but finger tapping test was negatively skewed. The only data that was not skewed was the mean frequency of finger tapping of dominant hand. The means and standard deviations of choice reaction time were 429.7 msec and 109.8 msec (2 choice), 493. 6 msec and 92.0 msec (4 choice). The results of simple reaction time were 254 msec (mean) and 55 msec (standard deviation). The mean frequency of finger tapping of dominant hand was 77.2 and that of nondominant hand was 64.9. The results of 2 choice reaction time test and finger tapping of dominant hand showed statistically significant sex difference. Factor analysis showed 2 factors, 1st reaction tests and 2nd tapping. The mean frequency of finger tapping had negative weak correlation with other reaction time test results. This computerized neurobehavioral tests may be widely applied in the other future studies, and is to be improved for the practical purpose of the occupational neurotoxico-logical area.