Previous research has suggested a high level of sexual activity among students, often involving unprotected intercourse. To better understand what factors contribute to consistent use of effective contraception, the relationship between sexual knowledge and sexual behavior and the relationship of sex guilt to sex knowledge were investigated in a pilot study involving 142 college students enrolled in a human sexuality course. Students completed the knowledge portion of the Sexual Knowledge and Attitude Scale, the Mosher Sex Guilt Scale, and the Sexual Behavior Checklist, as well as measures of self-esteem and a demographic and personal history questionnaire. The knowledge, guilt, and behavior measures were readministered at the end of the quarter. Results showed that, in general, actual knowledge had no bearing on sexual behavior; however, those who were more active perceived themselves as knowing more. Sexually active males, but not females, perceived themselves as knowledgeable about contraception. Those with high sex guilt tended to be less sexually active, but also less knowledgeable. The findings suggest a need for research to look at factors most directly relevant to responsible sexual behavior for unmarried, sexually active young people. (JAC)