Axiomatic theory construction was used in this study to analyze the likelihood of participation in premarital sexual intercourse by college women. The sample consisted of 754 never-married female students enrolled in a midwestern, residential university who responded to a sexual attitudes and behavior survey. Forty-eight empirical propositions concerning premarital sexual intercourse were tested, nineteen of which were found to be statistically significant. Three derived propositions were reformulated from these findings, which in turn were utilized to develop two middle-range theories: commitment theory and cultural milieu theory. These theories clearly demonstrate the role of changing personal and societal attitudes toward sexuality and perceived partner commitment in the decision to become sexually active.