High-commercial-value products are often susceptible to food fraud. Among them, Iberian dry-cured ham is highly appreciated due to its particular and sensory, but also nutritional, properties. There are four different Iberian ham categories (namely bellota, recebo, cebo de campo and cebo), which depend on the rearing system of the pig during the last stage of the fattening phase. However, there is still a lack of a normalized and robust method capable of authenticating the different product categories and, therefore, preventing mislabeling. In this work, we characterized the polymorphism of eighty raw lipid extracts belonging to the four categories of Iberian pig by using DSC and synchrotron radiation XRD techniques. The results showed that bellota and recebo samples exhibited essentially the same crystallization and polymorphic behavior and this was significantly distinguishable from that of cebo de campo and cebo categories. Crystallization and melting temperatures of bellota and recebo samples were significantly lower than those of cebo de campo and cebo, due to its more unsaturated fatty acids composition. Furthermore, lower amount of polymorphic forms was detected in bellota and recebo. By considering the differences in rearing systems of the pigs, we concluded that the key factor which determined the polymorphic behavior of Iberian pig lipid extracts was not the physical exercise practiced by the pig, but the inclusion of acorns in the feeding system. This work demonstrated that crystallographic techniques, like DSC and XRD, may be promoted to be used as fingerprinting tools for the authentication of high-value food products.