This study´s objective was to identify the effectiveness of bed bath video during simulation in the performance of undergraduate student skills. Method. This is a randomized, blinded clinical trial. The sample consisted of students of the second year of nursing graduation who were divided into two groups: intervention group (students who simulated bed bath using the video) and control group (students who simulated bed bath without the video). The students attended an expository dialog class about bed bath, structured on the basis of literature and that subsidized the elaboration of the video and the instrument to evaluate of the performance of the abilities. After the class, the subjects were consulted about the desire to participate, and those who agreed, signed the consent form. After the theoretical class, students were invited to attend the UNIFESP Skills and Simulation Teaching Center and were randomized to one of two groups (control or intervention), according to the sequence determined by the Random System. Randomization was carried out by a teacher who did not participate of any phase of this study, with masking of this phase. After randomization, the student was instructed to perform the bed bathing procedure on the low fidelity manikin, based on the knowledge obtained in the theoretical class, and no guidance was given at this time. At this stage, the teacher evaluated the student's skills through the checklist. It is emphasized that this teacher was not informed if the student evaluated was of the control group or intervention, and there is masking of this phase. The instrument for evaluating the performance of bed bath skills was the previously prepared and validated checklist called "Instrument for bathing in the bed - IABL", which presented good internal consistency in the validation study (Cronbach's alpha = 0.896) . This instrument is composed of three topics (nursing orientation, material preparation and procedure) and 56 items, whose scores vary from 0 to 56 points, in which the higher the score the better the students' abilities performance. Each item of this instrument was observed during the execution of the procedure before and after the simulation and was considered as executed properly (1 point), inadequate (0 point) or not performed (0 point). The performance of each student was analyzed by adding the scores of the items of the instrument. Subsequent to this first evaluation, the students, both in the control group and in the intervention group, received the intervention by another teacher. The students of the control group performed the simulation of the bed bath procedure, with the aid of a tutor and the intervention group simulated the bed bath while watching the video, under the supervision of the tutor. The tutor, from both groups, acted as facilitator of the teaching-learning process, according to the needs presented during the simulation period. At the end of the simulation, the student of both groups was instructed to perform the bed bath procedure once again, and no guidance was given at this time. The performance of the student's abilities was evaluated by the same instrument and by the same teacher of the first evaluation. Prior to the collection, the research project was submitted to the Research Ethics Committee and the data was collected after its approval.