A follow up of a cohort of 736 healthy full term children with exposure to cows' milk based formula and breast milk from donors on the maternity ward was performed. The children were divided into three exposure groups according to the feeding patterns on the maternity ward. Group 1 received only mother's milk, group 2 mother's milk and human donors' milk, and group 3 received mother's milk, donors' milk and cows' milk based formula. The children were investigated at 7 years of age, by examining their medical files, and at 11 and 14 years, by questionnaires regarding symptoms of atopic disease. No significant differences between the three groups at follow up were found in the cumulative incidences of atopic diseases. The amount of formula given did not affect the risk of developing atopic disease. Children with a family history of such diseases ran the same risk of subsequent atopic disease whether they were fed formula or breast milk alone. Cows' milk based formula given on the maternity ward does not seem to increase the risk of developing atopic disease.