This study examines the relationships among need for cognition, leisure life, and academic life of middle school students. The subjects were 97 males and 99 female juniors selected from three middle schools in Seoul. Data was collected through questionnaires. Students' academic life was measured by two criteria: interests in subjects and grades. Students' leisure life was also measured by two criteria: currently enrolled extra-curricula activities at school and preferred leisure-time activities if not limited by time or money. The summary of results are as follows : (l) need for cognition was more highly and positively correlated with the interests in subejcts which need more cognitive activities (Korean, mathematics, science) than the interests in subjects which need less cognitive activities (music, art) ; (2) need for cognition was significantly and positively correlated with all grades regardless of the types of subjects ; (3) need for cognition showed no differences according to the types of currently enrolled extra-curricula activities at school ; (4) need for cognition was more highly and positively correlated with preferred cognitive leisure-time activities than preferred non-cognitive leisure-time activities. These results suggest that need for cognition might play an important role in students' academic and leisure life especially when external conditions such as pressure for school achievement or time are controlled.