The occurrence and amount of residues of ochratoxin A (OA) in poultry tissues and organs were investigated in a trial aimed at measuring the effects of contamination approaching the patterns more frequently found in natural situations (i.e., small doses of OA in the diet for long periods). Hubbard male broilers and laying hens were treated with an OA-contaminated feed (50 ppb) from the 14th day of age onward. Both groups were further divided into subgroups, some of which underwent continual treatment (64 and 169 days, respectively) and others that were withdrawn from administration (maximum 28 and 82 days, respectively). Determination of residues was performed by high performance liquid chromatography. Residues in liver were higher in broilers (up to 11.0 ppb) than in hens (1.5 ppb), whereas the reverse occurred in kidney (up to .8 and 5.8 ppb, respectively). Residues (.8 ppb) were also in hen thigh muscle but not in breast muscle. Residues of OA in poultry appear to be of possible public health concern. Suggestions for monitoring are given.