This article describes the main laboratories that produced infant milk formula in Spain during and after the Spanish civil war. The statistical analyses of the composition data showed that there were differences between milks of the first and second semester and between simple and acidified milks, while milks of the second trimester were not different (in comparison with first and third trimester milks). The main differences were due to the fat content, although worth noting the excess of carbohydrates in the majority of the samples.