We report on the case of a bodybuilder and powerlifter who suffered from triceps tendon rupture complicated by acute ulnar nerve compression syndrome. The diagnosis was made clinically, radiologically, and sonographically. Ultrasound was helpful to demonstrate a large hematoma at the site of the injury. Early surgical intervention confirmed the presence of the hematoma compressing the ulnar nerve and led to a complete restoration of ulnar nerve and triceps muscle function. Few reports on distal triceps rupture have been published but its complication by acute ulnar nerve compression has not been reported on yet despite the close anatomical relationship of both structures.