Enrollment success at private colleges was examined, based on a national study of private college presidents. Enrollment success postulated that colleges will experience enrollment stabilization or improvement if they function at a relatively fixed rate of growth over an extended period. The study was also based on the systems concept, which recognizes that multiple factors together affect enrollment. Attention was directed to the effects on enrollment of selected college characteristics, marketing practices, and presidential leadership. Questionnaire responses from 327 presidents from 43 states indicated that one-third of the colleges exhibited 10-year 1974-1984 nonsuccessful enrollment histories. Interviews were also conducted with private college presidents, administrators, and faculty to examine the college's enrollment condition, curricular and administrative structures, and marketing systems. Findings include: marketing practices employed by the colleges appear to be independent of college characteristics such as location, size, and age in terms of their effect on enrollment; and marketing practices are often selected because they have been useful at more successful colleges. Eight action strategies are recommended for private colleges. (SW)