Scrotal enlargement and pain of rapid onset prompted a 28-year-old man to seek medical attention. The testicle was displaced posterior and inferior in the engorged scrotum and was difficult to palpate. A hydrocele may develop from trauma or inflammation of the tunica vaginalis testis, which can impede its ability to absorb secreted fluids. These fluids accumulate in the potential space between the anterior and posterior tunica, creating the hydrocele. This patient’s hydrocele had been present 1 year earlier when he underwent a vasectomy. The practitioner who performed the vasectomy drained the hydrocele by needle aspiration in order to facilitate the elective sterilization. At that time, 7 oz (more than 100 mL) of fluid was drained. The onset of the first occurrence was very gradual and painless. CPT Kenneth S. Brooks, PA-C, of Camp As Sayliyah, Doha, Qatar, writes that needle aspiration and drainage is not curative. Virtually every hydrocele managed this way recurs. Transillumination is not diagnostic. A loop of small bowel in the scrotum would also transilluminate. In this case, however, the history of previous hydrocele made the differential diagnosis of hernia unlikely, and indeed no inguinal ring defect was palpated. Because of the rapid onset of swelling and the patient’s discomfort, the risk of testicular ischemia warranted an immediate surgical referral. The hydrocele was repaired, and the patient’s recovery was uneventful.