It is generally accepted that there is no higher prevalence of renal disease in psoriatic patients, except in the case of secondary renal amyloidosis in psoriatic arthropathy. Contrary to this, however, some authors suggest that kidney diseases in psoriasis vulgaris may be more common and they presume the existence of 'psoriatic nephropathy'. We report a case of IgA nephropathy in a patient with psoriasis vulgaris as a contribution to the ongoing discussion concerning this entity of 'psoriatic nephropathy'. A 62-year-old man with a history of psoriasis vulgaris, without evidence of psoriatic arthropathy, was admitted to hospital for nephrotic proteinuria 6.74 g/day and a moderate decrease of glomerular filtration rate with a serum creatinine level of 213 micromol/L and creatinine clearance of 0.95 ml/s. Kidney biopsy revealed IgA nephropathy with vascular nephrosclerosis and tubulointerstitial nephritis. After 1 month of treatment with prednisone 1 mg/kg/day, proteinuria decreased to 2.45 g/day, and skin lesions almost completely resolved. About 10 cases of IgA nephropathy associated with psoriasis are referred to in the literature. We report an-other interesting case of IgA nephropathy in a psoriatic patient, as a contribution to the discussion regarding the hypothetical conception of 'psoriatic nephropathy'. We recommend routine urinalysis, careful examination of kidney function and a wider application of renal biopsy in psoriatic patients.