Brachial plexopathy can result from traction injury, radiation injury, local or metastatic cancer, hereditary, or idiopathic causes. However, brachial plexopathy resulting from malposition of an arm during sleep, similar to Saturday night palsy, has not been reported. We report a case of brachial plexus neuropathy that occurred after the patient slept on his shoulder and arm following excessive alcohol consumption on a Friday night.