OBJECTIVE: To evaluate the informed consent process for a clinical trial of intravenous doxycycline for rheumatoid arthritis. METHODS: Participants completed a self-administered questionnaire about the consent process at baseline and 16 weeks following enrollment in a clinical trial. RESULTS: Respondents (n = 30) affirmed voluntary participation in the parent trial. Participants acknowledged hope and altruism as reasons for entering the trial more than expectation of personal benefit or outside influences. Many respondents did not understand randomization (14/30), placebos (15/30), or risks of study medications; 11/30 respondents believed that the study drug was completely safe. CONCLUSION: Respondents generally understood the experimental nature of the trial and confirmed their participation was voluntary. However, gaps existed in participants understanding of trial design, raising the question of whether they were adequately informed about the research study prior to enrollment. Further education of potential participants in clinical trials may be required to achieve valid informed consent.