Growth factors enhance tensile strength, angiogenesis and collagen synthesis in skin wounds. The effects were studied of a continuous intraperitoneal infusion of epidermal growth factor (EOF) on the mechanical properties of healing in linear full‐thickness wounds of the stomach, ileum and colon of young pigs (n = 16, mean(s.d.) body‐weight 20·1(1·9) kg). In half the animals an osmotic minipump was implanted into the peritoneal cavity to deliver recombinant human EGF at a rate of 0·5 μg kg−1 24 h−1. Animals were killed at 5 days and the integrity of a 20‐mm ring of intestine was tested for tensile strength. Breaking strength (gmm−2) of the intestinal wounds in untreated pigs (n = 8) was: stomach 28·0(2·0), ileum 46·8(4·8), colon 85·6(4·2). Intestinal wounds in pigs (n = 8) receiving supplemental EGF had significantly increased breaking strength: stomach 32·4(2·2) (P<0·05), ileum 56·8(5·4) (P<0·05), colon 96·0(3·8) (P<0·01) compared with untreated animals. At 5 days after the initial injury intraperitoneal EGF increases the tensile strength of intestinal wounds in pigs. Copyright © 1990 British Journal of Surgery Society Ltd.