A 38-year-old man with pulmonary tuberculosis developed purpura over both lower extremities and renal disturbance after starting antituberculosis treatment. A renal biopsy and skin biopsy were performed to diagnose the new clinical manifestations, and leukocytoclastic vasculitis with IgA and C3 deposition were detected. Henoch-Schönlein purpura nephritis (HSPN) was diagnosed on the basis of the clinical and pathologic findings, and prednisolone therapy was added. The skin lesions disappeared in 7 days after starting steroid therapy, and renal function gradually improved. These results suggested that the pathogenesis of HSPN might be the consequence of the deposition of the circulating immune complexes. The treatment of HSPN has been not established yet. We should consider how to use steroid therapy for HSPN and call attention to the recurrences of renal disturbance and pulmonary tuberculosis. It is thus recommended to follow patients with HSPN in tuberculosis for long periods.