Household demand for improved sanitation in developing countries is an important social and behavioral process with implications for public health, sanitation policy and planning, and sanitation design and technology development. 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 in Ghana are defined, measured in a survey, 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 representative national 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 discussed. The approach is useful for assessing behavioral indicators of sanitation demand in developing countries and suggesting where marketing approaches can and cannot work to accelerate adoption of household sanitation improvements.