Freezing is the most widely used preservation method for poultry meat; however, prolonged frozen storage can induce structural changes in muscle tissue that ultimately affect meat quality. Histological studies provide valuable insights into the extent of ultrastructural damage during storage under different conditions. In the present study, fresh broiler breast muscle and frozen samples stored under aerobic and vacuum packaging at −12 ºC, −18 ºC, and −24 ºC for up to 12 months were examined histologically to assess the structural integrity of muscle fibres during storage. A total of 270 frozen broiler samples were collected from a commercial processing plant and stored under the specified conditions, while freshly slaughtered breast samples served as controls. Histological evaluation of fresh breast muscle revealed intact fibres with no noticeable structural alterations. Up to 90 days of frozen storage, the muscle tissue maintained its integrity with minimal changes. At 180 days, mild separation of muscle fibres was observed, which may be attributed to proteolytic activity and physical stress during storage. At extended storage periods of 270 and 360 days, clear separation and tearing of fibres and bundles were evident in all treatments, irrespective of storage temperature or packaging method. These changes were likely due to the formation of intracellular ice crystals, which exert mechanical stress on the muscle ultra structure. The study concludes that the histological integrity of broiler breast muscle is preserved up to 90 days of frozen storage, with only minor alterations evident by 180 days, whereas prolonged storage beyond this period results in significant structural damage.