In this study of adult part-time baccalaureate students at a midwestern private liberal arts college, prior learning assessment (the PLA portfolio process) significantly predicts persistence. Logistic regression results indicate that completers of the PLA portfolio process increase their estimated probability of persistence dramatically;Part-time adult students in higher education are likely to drop out. Adult students had dropped out at double the rate of traditional age students (45% versus 23%) in a 1992 study of the 1989 entering class. In a 1994 follow-up study, highly non-traditional students (attended part-time, worked full-time, had dependents, and delayed entry into college) were the least likely to have persisted. Among highly non-traditional students, 54% had dropped out 5 years after their 1989 entry;Researchers have identified a set of background factors and process factors that play significant role in persistence. The background variables are: age, gender, educational attainment of spouse and parents, work intensity (full-time or part-time), high school performance, and prior college credits. Life changes (such as divorce, childbirth, death or illness, and job change) influence the decision to enter higher education and the decision to leave. The outcome variables (grade point average, enrollment status, financial aid, academic and social integration, and disposition) directly influence the decision to persist;Disposition factors are confidence, goal clarity, commitment, satisfaction, and sources of support;The complex interplay of background, motivation, academic performance, PLA portfolio participation, and life changes affects adult student progress throughout the process. The significant variables predicting persistence for this study are grade point average, number of prior college credits, and participation in prior learning assessment. Demographic variables were not significant;Few interventions by adult educators can have as dramatic effect on persistence as the PLA portfolio process. Students within this sample who complete the PLA portfolio process increase their probability of persistence by a minimum of 45% to a high of 281%. Students with mean GPA and mean prior credits increased their probability of persistence by 106%. Three fourths of eligible students who completed the PLA graduated versus 39% of those who did not.