Beta-endorphin is one of the important members of the body-produced (endogenous) opioid peptides. Because of its pain relieving properties, it is regarded as an answer of the organism to stress. In this study, clinically healthy and nonpregnant 6 brown swiss hybrid cows at the aged 3-5 years of age, brought to the slaughterhouse which belongs to same company, were used. Blood samples were collected into anticoagulant free tubes from vena jugularis 20 minutes before the slaughter (Group 1); from flowing blood during bleeding (Group 2); from flowing blood, 3 minutes after slaughter (Group 3). Blood serum beta-endorphin levels were determined using beta-endorphin ELISA kit. Serum beta-endorphin levels for groups 1, 2 and 3 were determined as 157.0±23.1, 262.0±35.8, 574.3±95.4 pg/mL, respectively. There was significant differences in the serum beta-endorphin levels before, during and after slaughter. As a result, it has been revealed that halal slaughter provides relief in animals instead of pain through a beta-endorphin reaction.