The incidence of atopic manifestations due to cow's milk proteins was analysed in five groups of 15 newborns considered to be at risk for atopy because of a positive family history. All infants were studied over a 4-month period. The infants received either an adapted formula (AdFo), breast milk or a new hypo-allergic formula (HAF). Atopic manifestations appeared in 1 out of 15 breast-fed infants compared with 18 out of 45 infants fed with an AdFo. None of the infants receiving the HAF (exclusively from birth for 2-4 months) developed symptoms of atopy. Symptoms in each infant receiving an AdFo (n = 18) disappeared with the HAF. Although the results of this study are promising, data on a larger population and double-blind investigations are needed before firm conclusions can be drawn.