We report on a small (11 cases) outbreak of hepatitis A (HA) which occurred in the village of Narzole in the province of Cuneo, Northern Italy. Cases were reported during the period December 1993-March 1994 and centred around a Christian community centre caring for broken homes. Eight cases were children aged 7-13 and three were adults. The incidence for all ages was 354.8 per 100,000 inhabitants. Due to local resistance to the investigation of the outbreak we were unable to identify the source of the outbreak. Marginal and average costs were identified during the outbreak using a proforma and include costs of the investigation. The mean costs per case were $7899 (average) and $1793 (marginal). The main cost generators were costs of care if average costs only are considered (81% of total costs) or loss of productivity if only marginal costs are calculated (60% of total marginal costs). Small epidemics such as the one described appear to use a considerable amount of health care and personal resources. However, when marginal and opportunity considerations are applied (value of opportunities foregone for alternative use of resources), such costs decrease. This is especially valid for all treatment costs, as the majority of hospital running costs are fixed. The small number of cases and the high hospitalization rate (100%) make the epidemic of uncertain extrapolation.