This study investigated the relationship between neurobehavioral performance and pulmonary function in young and middle adults. Data were collected from 178 subjects (88 male, 90 female) aged 20-50 years. Neurobehavioral performance was assessed by the Korean version of The Swedish Performance Evaluation System (SPES-K), on five items: simple reaction time, symbol digit, digit span, and finger tapping speed for dominant and non-dominant hands. Pulmonary function, as indicated by the 1-s forced expiratory volume (FEV1), was measured according to American Thoracic Society criteria and the potential association was analyzed by linear regression. For simple reaction time, symbol digit, and digit span, the performance of subjects with FEV1 levels exceeding 3.29 l was 2-4% greater than those with the lowest levels of less than 2.60 l, after controlling for the effects of age, sex, education, smoking, and height. Finger tapping speed, however, did not show any significant association. These findings suggest that pulmonary function may influence neurobehavioral performance, especially cognitive abilities, throughout adulthood.