Systemic lupus erythematosus is an uncommon disease in men. The clinical and pathological features and prognosis in 50 male patients with lupus nephritis (LN) and 50 age-matched female patients with LN were analysed. The age at which the disease began and the diagnosis was made was generally older in the male. The incidence of LN was higher in the male than in female (P < 0.01). The incidence of types IV and V LN was more common in the male than in female. Type II LN was not found in male patients. Proteinuria over 3.5g/24h and renal failure were more common in the male than in female (P < 0.05). The three most common clinical manifestations in male patients were irregular fever, skin rashes and painful joints. Rashes, hepatomegaly and neuropsychiatric dysfunction were more common in the male than in female. The patients were followed up one to twelve years. The rate of recovery and improvement was lower, but that of relapse and mortality higher in the male than in female.