Oral BCG vaccine, either liquid or liophyllized, or a placebo was administered in three monthly doses to 3,684 healthy children. The study population was divided in two great groups, one to ninety days of age and the other from nine y days to jifteen years of age. A tuberculin test, with PPD (RT 23), 10 TU, was performed up to nine months later on each child, corsidering a nodule layer than five millimeters as a positive test. A positive incidence of 37.6% and 21% was found for the younger and the older age groups, respectively, who reccived liquid BCG. The children who took liophyllized BCG or placebo showed significantly smaller incidences. If allerginization moy be valued, then it can be seen that there is significant absortion, especially in the younger subjects