The treatment of olecranon fracture-dislocations (OFDs) remains challenging. OFDs are often misdiagnosed as Monteggia lesions, and the real frequency is actually higher. However, studies on OFDs are limited. This study aimed to report on the surgical management of OFDs and to highlight the importance of three-dimensional computed tomography (3D CT) evaluation in the treatment of OFDs. The study participants included 18 patients (11 men, 7 women, mean age 44 years (range 24-78) with OFDs. Each patient's medical records, radiographs, and 3D CT scans were reviewed for demographics, injury details, operative findings, and information about radiological and functional outcomes. The patients were divided into 2 groups according to the direction of the dislocation: the posterior dislocation group (group 1, 7 patients) and anterior dislocation group (group 2, 11 patients). The clinical evaluation was performed according to Broberg-Morrey and the American Shoulder and Elbow Surgeons-Elbow (ASES-E) scoring systems. The mean follow-up period was 39 months (range 25-62 months). The Broberg-Morrey results were excellent in 4, good in 9, fair in 3, and poor in 2 patients. The mean ASES-E score was 84.83 (range 48-100) points. There were signs of ulna-humeral arthrosis in 5 elbows. Arthrosis was graded as grade 1, grade 2, and grade 3 in 3, 1, and 1 elbows, respectively. Partial sensory recovery was observed in one patient with postoperative ulnar neuropathy at the last follow-up visit. OFDs are complex injuries of the proximal ulna and may involve the radial head, coronoid process, and lateral collateral ligament. The effective treatment of OFDs begins with the proper identification of the injury with 3D CT. A secure fixation including the coronoid process is mandatory for the elbow joint stability. Insufficient restoration of the trochlear notch may lead to problems with loss of motion and arthrosis. Although an application of a pre-contoured locking anatomical olecranon plate can simplify the fixation procedure in most cases, the surgeons' equipment should also include radial head implant, coronoid plates, headless screws, small cannulated screw system, suture anchors, fluoroscopy, and articulated external fixator.