Broiler chickens were fed on a commercial diet containing 0·0125% clopidol for 34 days. They were killed 0–10 days after withdrawal of the premedicated feed and clopidol was determined in liver and muscle samples by a sensitive gas‐liquid chromatography (g.l.c.) method. During the first two post‐withdrawal days the clopidol concentration in the liver decreased rapidly from 7 to 0·5 mg/kg and the level in muscle declined from 3 to 0·1 mg/kg. There was little decline in the clopidol concentrations from days 2 to 10, the levels during this period being 0·2–0·8 mg/kg in liver and 0·05–0·2 mg/kg in muscle.