Hemarthrosis occurring after arthroscopic surgery for lesions of the shoulder joint is a very rare complication that can develop due to an injury to the blood vessels when an anterior portal is formed. This is a complication that rarely develops in patients who are taking antithrombotic drugs or who do not have associated diseases, such as thrombocytopenia. We report a case of hemarthrosis that occurred after performing arthroscopic surgery to repair a rotator cuff tear in a patient with a stenosis in an arteriovenous fistula for hemodialysis in the ipsilateral upper arm.