Population growth and the unknown consequences of climate change emphasize the need for alternative water sources. Greywater reuse is one of the main options available but such alternatives are poorly accepted by the public. In this research, our aim is to understand how greywater reuse is accepted, with a major emphasis on risk and personal involvement. An online questionnaire was completed by 252 people. The participants lived in the city of Nantes (France). To determine the possible effect of personal involvement and risk perception on greywater acceptance, a Bayesian linear regression was realized in order to determine with certainty the most probable model. Results show that acceptance of greywater reuse is significantly predicted by perceived personal exposure to water shortages and droughts. It also appears that perceived health risks related to greywater reuse work as a brake to greywater reuse acceptance, as well as age and the possession of a rainwater recovery system. Results are discussed in terms of how to inform and involve the population in greywater reuse by reducing risk perception and promoting personal involvement.