Five hundred ninety-five students enrolled in undergraduate classes in psychology and business administration at the University of Maryland completed an anonymous questionnaire inquiring about their use or nonuse of marijuana, their reasons for using or not using the substance, and their attitudes toward the legal penalties for marijuana possession and toward the question of legalization. The availability of some comparable data from two previous unpublished surveys, made in 1967 and 1968, made it possible to examine trends in responses to some of the items. The study reveals trends in the direction of (1) more widespread use of marijuana among undergraduate students, (2) a greater increase in marijuana use among female respondents than among males (although it remains true that a larger proportion of males than of females has tried the drug) and (3) more widespread feeling that the legal penalties for marijuana possession are too severe and that marijuana use should be made legal. There is also less extensive use among freshmen than among upperclassmen and more common use among students living off-campus and not with their families than among dormitory residents or students living with their families. A sample questionnaire and statistical tables are included. (Author/SW)