The perceptions of patients regarding the benefits, disadvantages, and importance of their participation in a long-term cancer chemoprevention trial, the Isotretinoin-Basal Cell Carcinoma Prevention Trial, were assessed through a questionnaire mailed at the conclusion of the 3-year treatment period of the trial. Responses were evaluated overall, as well as within subgroups defined by sex, age, education level, treatment group, presence of side effects, and the number of skin biopsies performed during the 3-year intervention phase. Overall, "careful medical follow-up received" (43%) and "being part of a research effort" (24%) were the most frequently cited important benefits, while the "amount of time taken to attend clinic" (32%) and "side effects" (20%) were the most frequently cited unpleasant aspects of trial participation. Most surveyed patients viewed the study as "very or extremely important" to their general health (62%) and their skin cancer condition (88%) and, as a result of participation, felt "much or somewhat better" physically (52%). The majority indicated that they would "definitely or probably" be willing to take part in another research study (79%) and take the study medication, if it were shown to be effective in the trial (78%). Overall and subgroup data provide important insights into patient motivations and attitudes regarding cancer chemoprevention trial participation, adherence, and satisfaction.