The purpose of this article is to document a rotator cuff tear sustained by an elderly woman performing progressive resistance training (PRT) in a recent randomized controlled clinical trial. The patient was a sedentary 73-y-old Caucasian woman. Investigation revealed an acute, full-thickness tear of the right supraspinatus secondary to performing a shoulder press exercise. Further investigation via MRI revealed degenerative disease of the acromioclavicular joint including lateral downsloping of the acromion and an anteroinferior acromial spur, which would presdispose to impingement. Conservative management was implemented in this case for over 6 months with minimal success. The patient remained functionally limited in virtually all activities of daily living. Given the medical history, health status, physical condition, and age of our patient, it is probable that degenerative changes predisposed the patient to the injury. To our knowledge this is the first published report of an older adult sustaining a rotator cuff tear during PRT.