To provide longitudinal data on the effects of tutorial programs on retention/attrition, data were collected on 487 students tutored by Tutorial and Referral Services of the University of Cincinnati and on 292 non-tutored students who requested the program's assistance in 1978-1979. These students were tracked through the 1981-1982 school year. Data were gathered and analyzed on grade point averages, continued enrollment versus dropping out or failing, and other factors. The tutored and nontutored students were very similar on such success predictors as incoming grade point average (18.3% lower than the mean), test scores (as much as 43% lower), high school rank, and status as a nontraditional student (more than half were over 22 years old). The results of the study include the following: (1) 36% of the nontutored group failed to enroll in 1979-80, whereas only 18.5% of the tutored group failed to enroll that year; (2) 24.3% of the remaining nontutored students left during 1980-81, compared to only 9% of the remaining tutored students; (3) students who left, among both groups, usually did not return in subsequent years; (4) the small group of tutored students who used the tutorial services most frequently and for the longest period were the most likely to be retained; (5) tutoring made a substantial difference in the retention of students over 30 years of age, students under 25, and black students; and (6) the greatest differences were found for blacks than for the other groups. Eight tables of data are appended. (KM)