The mastery of effective study habits remains one of the chief goals of university students. Even casual observation reveals dramatic differences among students in choice of places to study. Some students try to avoid other people at all costs, leaving their own rooms if a roommate is present, while others seek out the visual presence of other people in large study halls and maintain that they need some form of auditory and visual stimulation lest they lose interest and alertness. A previous investigation of library study places showed some students immediately tried to lose themselves in the stacks while others headed straight for the public areas (Sommer, 1966). The assumption made by some librarians (Ellsworth, 1965) that almost all university students prefer private sn~dy carrels was not supported by these data. In view of the gross differences in kinds of environment used, it seemed reasonable to ask whether personality factors influence choice of study places. A 12-item questionnaire dealing with study habits was administered to 130 st~ldents in introductory psychology classes along with the Maudsley scale of introversion-extroversion. The group was then divided into approximate thirds on the basis of their scores on the Maudsley, scores of 3 to 22 were introverts, 23 to 31 a middle group, and 32 to 46 extroverts. All differences were evaluated by chi square tests. There was no difference in the most effective snidy time, but introverts tended to study more on Friday nights than extroverts. Introverts tended to study while sitting at a desk or table, while extroverts preferred to sit on a couch or a bed. Extroverts also snacked considerably more than introverts ( p < .001), and smokers tended to smoke more while studying ( p < .01). Over 95 % of the 130 Ss took breaks during study periods, but there was a significant trend for extroverts ( p < .02) to spend the break with other people. Finally, there was an interesting trend ( p < .05) for introverts to earn higher grade point averages than extroverts: 4196 of the introverts reported GPAs of B or better, 29% of the middle group, and 24% of the extroverts. While these differences do not mean that study places must be prescribed like medicines according to individual personality, they do suggest some degree of flexibility in planning, so that an individual can select the kind of space he wants and adapt it to his needs. Built-in furninire and fixtures and homogeneous study halls in the library or dormitory prevent needed flexibility.