An ABC multiple-baseline design across three students diagnosed with an emotional impairment and/or developmental disability was used to evaluate handwashing behavior after offering a video model and then providing individualized visual handwashing feedback. The visual feedback was delivered by applying a substance that fluoresced under ultraviolet (UV) light, and these visual cues provided information regarding that student’s handwashing. The extent to which areas glowed under UV light provided feedback on the effectiveness of handwashing and served as a prompt for future handwashing behavior. The handwashing behaviors of three school-aged individuals were analyzed in terms of number of fluorescent spots on the hand and the total amount of time spent handwashing. Results indicate that the fluorescent visual feedback was acceptable and entertaining for students with emotional impairments and/or developmental disabilities, as well as an effective intervention to improve handwashing behavior for two of the students. (PsycINFO Database Record (c) 2019 APA, all rights reserved)