Adult rats of both sexes were given a single oral dose of [14C]patulin and were sacrificed at various time intervals from 4 hr to 7 days following administration of the mycotoxin. Two groups of rats were employed; the treated group had been exposed to daily oral doses of unlabeled patulin (dissolved in pH S.O citrate buffer) in utero and for 41–66 wk after weaning, while the controls were given the buffer only throughout gestation and for 38–81 wk after weaning. Approximately 49% of the administered14C radioactivity was recovered from feces and 36% from urine within 7 days after dosing. Most of the excretion of labeled material occurred within the first 24 hr. All of the14C activity detected in the urine samples was either metabolites and/or conjugates of the original [14C] patulin. About 1–2% of the total radioactivity was recovered as14CO2from expired air. Carbon‐14 radioactivity in various tissues and organs was determined throughout the 7 day period; the most significant retention site was the red blood cells.