We examined the cause of death during a 12-month period (1995/96) in all consecutive patients admitted to hospital with leptospiral infection in Seychelles (Indian Ocean), where the disease is endemic. Leptospirosis was diagnosed by use of the microscopic agglutination test and a specific polymerase chain reaction assay on serum samples. Seventy-five cases were diagnosed and 6 patients died, a case fatality of 8%. All 6 patients died within 9 days of onset of symptoms and within 2 days of admission for 5 of them (5 days for the 6th). On autopsy, diffuse bilateral pulmonary haemorrhage (PH) was found in all fatalities. Renal, cardiac, digestive and cerebral haemorrhages were also found in 5, 3, 3 and 1 case(s), respectively. Incidentally, haemoptysis and lung infiltrate on chest radiographs, which suggest PH, were found in 8 of the 69 non-fatal cases. Dengue and hantavirus infections were ruled out. In conclusion, PH appeared to be a main cause of death in leptospirosis in this population, although haemorrhage in other organs may also have contributed to fatal outcomes. This cause of death contrasts with the findings generally reported in endemic settings.