The aim of this study was to determine how different doses of phytase in diets with extruded soybean seeds and rapeseed meal affected pigs’ growth performance, meat quality, bone mineralization, and fatty acid profiles. Sixty pigs were divided into three treatments by sex and body mass. Pigs were divided into starter (25 days), grower (36 days), and finisher (33 days) periods and fed with mash diets. No phytase was used in the control group diet, whereas in Phy1 and Phy2, 100 g and 400 g of phytase per ton of mixture were used, respectively. The feed conversion ratio and meat color were significantly correlated with phytase. Phytase supplementation had no effect on the growth of pigs, but total phosphorus was significantly increased in the bones and meat of the pigs. The enzyme additive reduced the C22:4 n-6 acid content in the meat, whereas other results were not significantly affected. The data suggest that the addition of phytase at a dosage of 100 g/ton to diets with extruded full-fat soya seeds and rapeseed meal can be valuable, as it reduces the FCR and increases the P content in the meat and bones.