A randomized controlled trial was conducted to determine if a videotaped presentation by a physician conveys information more effectively than an in-person discussion by the same physician using the identical script. Two hundred one patients undergoing colonoscopy were enrolled in the study. Patients were randomly assigned to one of three groups: video plus discussion, video alone, and discussion alone. A validated, 13-item knowledge test and the State-Trait Anxiety Inventory were administered to all patients. Mean number of correct test answers for video plus discussion was 11.04; for video alone, 10.70; and for discussion alone, 9.61. ANOVA with planned orthogonal comparisons showed that the patients in the two video groups had significantly better scores (p < 0.001) than those in the discussion-only group. No difference was noted between the two video groups (p = 0.32). Anxiety did not increase with increased understanding of the risks and benefits of colonoscopy. This approach may work as well for other invasive medical procedures and could save physician time while laying a foundation for a more personalized discussion.