A 49-year-old man presented to the emergency department (ED) with shoulder pain after intramuscular injection of heroin into his right deltoid muscle. Point-of-care (POC) ultrasound identified a subdeltoid abscess, and ultrasound-guided aspiration of the fluid collection was performed. The patient was admitted and improved on antibiotics and made a complete recovery. POC ultrasound and ultrasound-guided aspiration can assist in the diagnosis and treatment of deep musculoskeletal abscesses. [West J Emerg Med. 2014;15(7):–0.]