The nutritional quality of meat and the health-promoting properties of intramuscular fat from randomly selected rearing pigs of the native Puławska breed (PUL, n = 15) and its crossbreeds with the Polish Large White breed (PLW × PUL, n = 16) and the DanBred hybrids (DAN, n = 17) were compared. The typical commercial fattening period was carried out up to 80 days of age. The initial body weight of PUL weaners was 30.55 kg (±3.98 kg), that of PLW × PUL weaners was 30.00 kg (±4.29 kg) and that of DAN weaners was 30.70 kg (±3.40 kg). The protein content and energy value of the complete feeds (Grower and Finisher) were 165 and 155 g/kg, and 12 and 11.8 MJ/kg, respectively. The research material consisted of samples of Longissimus lumborum and Semimembranosus. The chemical analyses included the determination of proximate composition, fatty acid content and amino acid concentration. The lowest fat content was found in the meat of the Puławska pigs, while the highest was found in the DanBred fattening pigs. The highest content of SFAs and MUFAs was found in the meat of DanBred hybrids, while it was significantly lower in Puławska pigs. The genetic group did not affect the content of PUFAs, including n-3 and n-6. Significantly lower and more favourable atherogenic and thrombogenic indices were found for the intramuscular fat of Puławska pigs. The very limited effect of the genetic group on amino acid content was observed, except for that of serine, histidine and lysine. In general, the meat of pigs of the Puławska breed showed the highest nutritional value and the most favourable health-promoting properties.