For handwashing to be effective, it needs to be practiced consistently and thoroughly. Even when people have access to soap and water, and know how and why to wash their hands, many still do not properly wash their hands consistently at critical times. The handwashing behavior change challenge is not only to encourage people to wash their hands with soap, but to do so correctly and at all critical times.<br> Nudges are one example of a behavior change tool that can encourage people to wash their hands.<br> Although the evidence base for nudges is still emerging and nudges for handwashing have been tested primarily in single contexts or on a limited scale, this brief and infographic answer some frequently asked questions about nudges and provides examples of how they have been used in efforts to increase handwashing.