This paper develops a behavioral approach to assess household demand for improved sanitation in Ghana . Adoption decision stages of preference, intention, and choice to install a toilet are defined, measured, and used to estimate sanitation demand, identify factors affecting demand at each stage, and classify households by adoption stage to identify targeted demand-stimulation strategies. Results from a sample of 536 households indicate that of 74% of households without any home sanitation, 31% have some likelihood of installing a toilet within the next year, but only 6% are very likely to do so; 62% had not considered the idea. Motivating and constraining factors are compared at each adoption stage and strategies likely to increase toilet installation in Ghana are discussed. Social Science & Medicine 2007; 64(12):2427-42.