In a consecutive series of 1207 major laparotomies, the incidence of wound infections, wound failures and chest complications was prospectively recorded; this allowed certain predisposing factors to be identified, both avoidable and unavoidable. Among the former were operative bacterial contamination, haemorrhagic and septic shock and the use of nasogastric tubes; the most important of the latter were male sex and pre-existing bronchitis.