The knowledge of the chemical composition of the pig diets provides decision-making for the obtaining of the maximum production performance of the animals. Therefore, the nutritional quality of commercial swine diets in each production stage was evaluated. Six different commercial diets used in IF Southeast MG, Rio Pomba Campus (Federal Institute Southeast MG, Rio Pomba) were collected, the analyses of moisture, mineral matter, crude protein, total phosphorus and water activity were conducted. The chemical composition found was compared with the information reported on the label as well as the nutrient requirements for each phase of the pigs. Some irregularities were observed when comparing the actual composition with that reported on the label. The pre-starter diet presented a moisture value above what is described on the product label. Regarding crude protein, the starter and grower diets did not meet the minimum levels specified on the label. As for phosphorus, the pre-starter and starter diets did not meet the levels shown on the labels. Regarding the crude protein requirements, the pre-starter diet presented value below and pregnancy and finisher diets showed values far above that required by pigs in these phases. For the water activity, no diet posed risk to fungal growth.