In 1986, a Program on Prevention of Allergic Diseases was initiated in our country which was possible on account of the organization conditions of our health system. The program includes IgE measurement in umbilical cord serum by means of an ultramicroanalytic technique for IgE quantification. This is an heterogeneous sandwich-type immunoassay that requires only 10 microliters of reactive on each reaction step and its processing is carried out on the Cuban SUMA equipment. Two groups of children were selected and followed-up: group I included 80 one-year-old infants and group II included 60 18-months-old infants. Both groups followed hypoallergenic diets and had minimal exposure to aeroallergens within their microenvironment. Results were compared with those of respective control groups. Compliance of both groups with the prophylactic measures brought about a reduction in the existence of allergic diseases and a comparison with the control groups offered a statistically significant difference (p less than 0.001). Similarly, incidence of asthma was found more reduced in groups I and II than in the control groups (p less than 0.001). Within the groups treated under the Program on Prevention of Allergic Diseases, IgE values were lower, while the control groups exhibited a higher number of infants with figures of 200 IU/ml or more (p less than 0.05). Our results support the usefulness of preventive measures in avoiding the presence of atopic diseases.