This paper presents the results of a survey of the costs of malaria falling on households in 6 Nepali districts. Information is presented on the age and sex distribution of cases, use made of sources of treatment other than those offered by malaria control agencies, expenditure on these treatment sources, and days of work and school lost. It is found that adults are more likely than children to be affected by malaria; that 47-77% of patients consult alternative sources of treatment, sometimes spending quite large sums; and that 6-14 days of work and 4-14 days of school were lost on average, the precise figure varying considerably by district and strongly influenced by species of parasite and delay before obtaining treatment from malaria control agencies. The question of the value of lost time is deliberately not addressed, since this requires detailed information on how the household responds to the illness of one of its members.