A 59-year-old woman with ulcerative colitis developed red eyes, pleural effusion, eosinophilia and urinary abnormalities after restarting of sulphasalazine treatment. Light microscopy of a kidney biopsy revealed segmental necrotizing glomerulonephritis without deposition of immunoglobulin or complement. Proteinase 3-antineutrophil cytoplasmic antibody (PR3-ANCA) titer was elevated at 183 ELISA units (EU) in sera (normal range less than 10 EU), myeloperoxidase-ANCA was negative. PR3-ANCA titer was 250 and 1,070 EU in pleural effusions on right and left side, respectively. Although cessation of sulphasalazine treatment resulted in improvements in fever, red eyes, chest pain, titer of C-reactive protein and volume of the pleural effusions, we initiated steroid therapy, because PR3-ANCA titer rose to 320 EU, eosinophil count increased to 1,100 cells/microl, and the pleural effusion remained. One month after steroid therapy, the pleural effusion disappeared, and PR3-ANCA titer normalized 3 months later. This case suggests that sulphasalazine can induce PR3-ANCA-positive necrotizing glomerulonephritis.