Summaryobjectives To describe global approaches to handwashing research in low-and middle-income communities, schools and health care settings using behavioural outcome measurement and temporal study design.methods Peer-reviewed and grey literature was screened for handwashing studies that evaluated behaviour change. Relevant articles were assessed by their research approach, including the investigator's selected outcome measure and time frame of various study components (e.g., formative research, intervention and evaluation).results The initial search yielded 527 relevant articles. After application of exclusion criteria, we identified 27 unique studies (30 total articles). Of the 27 articles, most were focused in the community setting. Fifteen (56%) documented observed handwashing behaviour, while 18 (67%) used proxy measures (e.g., soap presence, diarrhoea) and 14 (52%) used self-reported behaviour. Several studies used multiple outcome measures. While all studies had an evaluation of behaviour change, there was a dearth of studies that evaluated long-term maintenance of behaviour change after the intervention's conclusion.conclusions While the literature is replete with a variety of handwashing studies in community, school and health care settings, none have been able to definitively document long-term behaviour change, thereby challenging the sustainability of various interventions. Additionally, there is a need to better understand which research approach is most effective in promoting long-term behaviour compliance in global low-and middle-income settings.