Subacromial lipoma represents a rare cause of subacromial impingement syndrome (SIS). A 49-year-old male patient presented to clinic with progressive right shoulder pain and limited movement, ongoing for approximately 1 month. Magnetic resonance imaging (MRI) revealed a lesion, compatible with lipoma, extending through subacromial space and pressing on supraspinatus muscle. After histopathological verification of lipoma, mass was excised. Postoperatively, patient completed 1 month physical therapy and rehabilitation program. Patient was free of pain at 4-month follow-up. Subacromial lipoma should be included in differential diagnosis of SIS for patients unresponsive to conservative treatment; MRI is very useful to determine precise etiology and inform surgical treatment.