Studies have shown the efficacy of videos used in isolation to retain knowledge, acquire skills, and establish students' self-confidence. A few studies have investigated the efficacy of videos associated with simulations, while none of these studies have addressed bed bathing, one of the first procedures learned by nursing students.To test the efficacy of a video-assisted bed bath simulation on improving the performance of psychomotor skills of undergraduate nursing students.A randomized clinical trial.A Teaching Skills and Simulation Center at a Federal University in Brazil.All students regularly enrolled in the second year of the nursing undergraduate program at a Federal University, aged 18 years old, who had never performed a bed bath and had attended a theoretical class addressing the procedure (n = 56).The students were randomized into two groups: the Control group (n = 28) simulated a bed bath with the instructions of a tutor, while the Intervention group (n = 28) watched a video during the bed bathing simulation, under the supervision of a tutor. The performance of students concerning bed bathing was assessed twice (before and after the simulation) using a previously validated instrument.The psychomotor skills of both groups significantly improved in the second assessment, and the Intervention group scored higher (p = 0.003).The use of a video during bed bath simulations was efficacious for improving the performance of psychomotor skills of undergraduate nursing students.