Fracture of the fabella is rare, may be easily overlooked, and can be a clinically important cause of posterolateral knee pain following traumatic injury or total knee arthroplasty. To date, nine case reports of fabella fracture with radiographic documentation have been reported in the literature. This report documents a 55-year-old male pedestrian who was struck by an automobile and presented with radiographs demonstrating depressed lateral tibial plateau and proximal fibula fractures. Computed tomography (CT) was performed for surgical planning and demonstrated the additional finding of a radiographically occult nondisplaced fabella fracture. To the best of our knowledge, this is the first case in which CT documentation of a fabella fracture is reported. Fracture of the fabella is a rare but important clinical entity which may be overlooked clinically and radiographically. Clinical information can provide a high index of suspicion, and when coupled with radiographic and CT findings, may lead to the correct diagnosis. CT imaging of the knee may confirm a suspected fabella fracture or may help detect a radiographically occult fracture.