In a large randomized trial involving over 2,000 women with abnormal cervical cytology (pap smear), three clinic-based interventions were tested as strategies to increase return rates for screening follow-up: 1) a personalized follow-up letter and pamphlet; 2) a slide-tape program on pap smears; and 3) transportation incentives (bus passes/parking permits). The three interventions were evaluated using a 2 x 2 x 2 factorial design. Results of this study confirm a high rate of loss to screening follow-up (i.e., no return visits) among women with abnormal pap smears (29% overall), with substantial variability among the 12 participating clinics (13% to 42/%). For the sample as a whole, both transportation incentives and the combined intervention condition of personalized follow-up and slide-tape program had a significant positive impact on screening follow-up. However, transportation incentives emerged as the dominant intervention condition among patient subgroups that can be characterized as more disadvantaged socioeconomically and at higher risk of developing cervical cancer, including patients receiving care from the county health department (odds ratio (OR) = 1.51; P less than .05); patients without health insurance (OR = 1.77; P less than .01); and patients with more severe pap smear results (OR = 1.71; P less than .05). In contrast, among patient subgroups that can be characterized as relatively more advantaged and at lower risk of developing cervical cancer, only the combined intervention condition of personalized follow-up and slide-tape program was associated with a higher patient return rate. Subgroups reflecting this pattern included patients seen in noncounty clinics (OR = 4.54; P less than .05) and patients with less severe pap smear results (OR = 5.16; P less than .01). The implications of these findings are discussed in terms of designing clinic-based interventions to improve screening follow-up.