N‐formyl methionyl leucyl3H‐phenylalanine was used as a model bacterial chemotactic peptide to study the systemic metabolism and excretory pathways for such peptides in the rat. After intravenous bolus infusion, the peptide was rapidly cleared from the systemic circulation with a mean of 22% of the dose being excreted in bile over 2 h. In bile, 53% of radioactivity existed as intact peptide, the remainder was its degradation product,3H‐phenylalanine. No intact peptide was detected in urine. While previous studies have shown no significant absorption of F‐met‐leu‐phe from normal rat intestine, in the current studies ileal loop infusions of F‐met‐leu‐phe in hyperosmolar solution, to increase gut permeability, resulted in absorption of intact peptide which was recovered in bile. These studies show that bile is a major pathway for excretion of bacterial chemotactic peptide in the rat and confirm the potential for an enterohepatic circulation of peptides from the gut lumen under conditions of increased intestinal muc