Partial thrombosis of the corpus cavernosum is an extremely rare and likely underdiagnosed urologic condition. We discuss a case of a 25-year-old male who presented with severe perineal pain and was diagnosed with idiopathic proximal partial thrombosis of the corpus cavernosum via ultrasound and MRI. The patient experienced symptom resolution with evidence of disease regression on follow up MRI after treatment with direct oral anticoagulation. Further studies are needed to fully delineate the pathophysiology of this condition to facilitate development of standardized diagnostic and treatment algorithms.