A magnetic arm sling for immobilizing the arm of a patient. The magnetic arm sling includes an abdominal strap with a magnetically attractive member and an arm support with a magnetically attractive member. The arm support is worn on the patient's arm. The magnetically attractive member of the abdominal strap and the magnetically attractive member of the arm support form a magnetic bond to immobilizes the patient's arm. An abduction pillow with one or more magnetically attractive members may also be used with the magnetic arm sling.