Fifty patients with biopsy-proven glomerulonephritis and 100 sex- and age-matched controls (50 patients each with non-glomerular renal disease or acute appendicitis) were asked by questionnaire and a telephone interview whether they had been exposed to organic solvents. The questioning and the evaluation of the exposure, if any, was made without knowing the diagnosis of the interviewee. Fifty per cent of the patients with glomerulonephritis reported more than slight exposure, but only 20% of the controls. Exposure to organic solvents may often play a role in the causation of glomerulonephritis.