Bedside ultrasound has become an important diagnostic tool for emergency physicians. Clinical investigators have demonstrated that evaluating soft tissue infections with ultrasound is useful for the detection of subcutaneous abscesses. Bedside ultrasound of a preputial cavity abscess in the Emergency Department has not been previously described in the English medical literature. A preputial cavity abscess, a rare complication of balanoposthitis, is a collection of pus between the foreskin and the distal penis. This case report describes the use of ultrasound to diagnose a penile abscess and reviews the related literature.