The purpose of this study was to analyze and describe circumstances and clinical aspects of pectoralis major rupture in elderly patients compared with younger patients. Eleven patients were nursing home residents and two were community residents. All had severe pain with a large pectoral ecchymosis extending to the lateral chest wall and arm. Twelve patients experienced substantial blood loss (average, 2.3 g/dL hemoglobin), which resulted in hemodynamic decompensation in two of the patients, necessitating a blood transfusion. The most probable mechanism of injury was indirect, caused by a brisk tearing movement applied to stiff, atrophic muscle during commonly used nursing procedures for transferring, positioning, and dressing the patients. The authors suspect this injury to be more common than reported. Although surgical repair is not required in the elderly, a proper diagnosis is imperative because the injury has a severe clinical impact necessitating care and followup.