Abstract: The study aimed to determine physico-chemical characteristics and myofibrillar proteolysis of breast muscles from broiler chickens subjected to head only electrical stunning. Pectoralis major muscles were collected from un-stunned (N = 25) and electrically stunned (N = 25) chickens at a commercial poultry processing plant. All samples were analysed for pH, color values, shear force, cooking loss and desmin degradation at 0, 4 and 24 h postmortem. The head only electrical stunning had significantly improved cooking loss and lightness (L*) of the pectoralis major muscles. Besides, there was a tendency for the stunning regime employed in this experiment to cause more rapid degradation of desmin over the 24 h postmortem storage.