This study examines and analyzes the impact of mandatory enforced skill prerequisites on student enrollment patterns and course performance outcomes in the San Diego Community College District (SDCCD). This investigation uses a comparative framework that includes data from two semesters to assess the impact of the prerequisite policy. The implementation of mandatory prerequisite skills levels enforced at registration appears to have coincided with enrollment declines in the majority of disciplines and within individual sections included in this investigation. In several of the science disciplines,there has been a concomitant increase in the proportion of successful course grades and a decrease in student drops. The effect in the social sciences and languages has been less obvious in terms of student outcomes, but enrollment in general showed a decline even though the number of sections offered remained relatively constant over the two terms. The effects on student equity categories varied substantially among several disciplines analyzed. The effect of mandatory prerequisite enforcement does not seem to negatively impact any group in particular. Appendix 1 includes tables that contain data for each course and subject area while Appendix 2 contains data for each course and subject area by SDCCD college and Educational Cultural (Complex. Contains 12 references.) (VWC)