During the last 9 years, 32 cases of hemorrhagic fever with renal syndrome (HFRS) have been diagnosed in our institution. Seven patients died. Twenty-three patients were discharged healthy while in another 2 some degree of renal dysfunction, which remained stable 12-15 months later, was evident. In 12 out of the 23 healthy individuals thorough examination of renal function was performed 1-5 years after their discharge. Three out of the 12 had renal tubular acidosis (RTA) type I (distal), complete or incomplete, and 2 (1 of whom also had incomplete RTA) had reduced urine concentrating ability. The development of chronic renal dysfunction was independent of the clinical severity of the acute illness.