One thousand condemned pigs' kidneys were collected in February 2002 from two pig abattoirs in England to assess the possible contribution of ochratoxicosis to postweaning multisystemic wasting syndrome (pmws) and porcine dermatitis and nephropathy syndrome (pdns); 250 of the kidneys with macroscopic lesions consistent with nephrosis/nephritis (pale or white cortical lesions) were selected, and the concentration of ochratoxin A was measured in samples of renal cortex by high-performance liquid chromatography (hplc). Low concentrations were detected in 230 (92 per cent) of the kidneys tested, and in 41 (16·4 per cent) of them the concentration was below the limit of quantification of 0·2 μg/kg. In 187 (74·8 per cent) of the kidneys, the concentration was more than 0·2 μg/kg, and the highest concentration detected was 2·3 μg/kg. The mean (sd) concentration was 0·31 (0·33) μg/kg. The identification of ochratoxin A was confirmed by mass spectrometry. The concentrations of ochratoxin A did not exceed the threshold assessed by the Food Standards Agency to be safe for human food.