Hypersensitivity to cows’ milk has been suggested as a common cause of digestive, respiratory and skin disorder in infants.1–5 However, though most infants fed on cows’ milk develop antibodies to it,6 7 the evidence that illness commonly results is uncertain.8 The possible relationship of cows’ milk to ‘cot death’, infantile eczema and certain forms of gastro-enteritis merits discussion.