Previous estimates on the economic burden of lymphatic filariasis (LF) in India and elsewhere were primarily based on studies in rural areas. We investigated the treatment costs due to acute and chronic forms of LF in urban areas, where nearly one-third of the affected people live. Almost 98% of the patients with acute episodes of adenolymphangitis (ADL) underwent treatment and 49% of chronic patients also received treatment. The average treatment cost per ADL episode (n = 108) was Rs 22.21 +/- 53.84 (US dollars 0.46 +/- 1.12). The overall (n = 200) treatment costs incurred by a chronic patient per visit were Rs 16.71 +/- 62.36 (US dollars 0.35 +/- 1.30); for those who paid (n = 98) they were Rs 34.10 +/- 85.90 (US dollars$ 0.71 +/- 1.79). These costs are considerably higher than in rural areas. Government health centres and private practitioners were important sources of treatment. Treatments received from private practitioners were considerably more expensive than those from government health facilities. The cost of medicine accounted for 44% and 50% of the total expenditure on treatment for acute and chronic disease patients, respectively. The medical personnel from these treatment sources need to be trained on the new morbidity management methods, which are likely to be more effective than the current methods of treatment.