The present study aimed to study the effect of adding Iraqi rice bran protein isolate, Amber 33 variety, at different ratios (100, 200, 300) mg to manufactured yogurt to extend its storage life, in addition to the two control treatments Yc- without any addition and Yc+ to which the industrial antioxidant BHT was added at a concentration of 200 mg. The results showed no significant differences in pH values ​​between all treatments immediately after manufacturing, and a decrease in pH values ​​was observed with increasing storage period. The results also showed that the PV and ADV values ​​were close immediately after manufacturing, and these values ​​increased with increasing storage period. The total bacterial counts varied for the control treatments and the yogurt supplemented with protein isolate, as they increased with increasing refrigerated storage period. The results showed that all treatments were free of coliform bacteria, Psychrotrophic bacteria, yeasts, and molds throughout the storage period, while yeasts and molds appeared at the end of the storage period of 21 days for all treatments.