The aim of the study was to determine the correlation between some clinical parameters and histopathologic findings in patients with lupus nephropathy. Eighteen patients (17 female and one male) with the diagnosis of lupus nephritis were examined at the Nephrological Clinical of the Faculty of Medicine. Three to eight months passed between diagnosing systemic lupus erithematosus and kidney biopsy. At the time of biopsy the average age of patients was 33.3 +/- 2.9 years (18-52 years). In more than half of the 18 cases the disease was evidenced as nephrotic syndrome, but most of them had renal failure and increased blood pressure. In patients with diffuse proliferative glomerulonephritis proteinuria was significantly higher than in other histopathologic groups. Serum nitrogen was considerably higher while creatinine clearance was much lower in patients with diffuse proliferative glomerulonephritis than in other histopathologic groups. Circulating immune complexes were increased, and the complement (C3 and C4) concentration was slower in patients with lupus nephropathy, but the significant difference was present only when diffuse glomerulonephritis was compared to other histopathologic groups.