Objective: This study aimed to analyze the injury pattern and clinical importance of concomitant capitellar cartilage defects (CCDs) among patients treated surgically for radial head fracture (RHF)., Methods: A total of 74 patients who were treated surgically for isolated RHFs were retrospectively reviewed. Of these, 12 patients with CCDs (16.2%) were classified as Group I (10 men; mean age, 41.3±12.8 years) and the remaining 62 patients without CCD as Group II (control group) (48 men; mean age, 50.8±13 years). The mean follow-up was 21.3±3.2 months in Group I and 18.7±6.4 in Group II. In Group I, 11 patients underwent open reduction and internal fixation, whereas 1 patient was treated by radial head resection. The preoperative range of motion (ROM) was recorded; the severity of RHF was assessed using the Mason classification. The location, size, and thickness of CCD injuries at the time of surgery were also documented. At the final follow-up, radiological assessment was performed to determine the bone union, and clinical measurements, including ROM and the Mayo elbow performance score (MEPS), were performed. The clinical features of the 2 groups were statistically analyzed., Results: In Group I, 10 patients showed limited forearm rotation. CCD was located posterolaterally in 11 patients and anterolaterally in 1 patient. At the final follow-up, 11 patients from Group I who underwent open reduction and internal fixation showed complete union of RHF and full recovery of pronation and supination. According to the MEPS, 9 patients exhibited excellent results, and 3 patients exhibited good results. In Group I, RHFs were classified as Mason type II in 7 patients (58.3%) and type III in 4 patients (58.3%). In Group II, RHFs were type II in 45 patients (72.6%) and type III in 17 patients (27.4%). In comparative analyses, there was a significant difference in age (41.3±12.8 versus 50.8±13.0, p=0.041) between the 2 groups. Preoperative pronation/supination was higher in Group II (131.7±36.2) than in Group I (106.3±31.6) (p=0.021). There were no significant differences in sex (p=0.097), follow-up period (p=0.326), Mason type (p=0.482), preoperative extension/flexion (102.3±43.3 [Group I] versus 107.6±44.9 [Group II]) (p=0.584), final follow-up extension/flexion (133.3±10.7 [Group I] versus 126.9±21.2 [Group II]) (p=0.384), pronation/supination (151.2±9.1 [Group I] versus 151.2±13.3 [Group II]) (p=0.558), and the MEPSs (92.9±6.6 [Group I] versus 93.3±7.5 [Group II]) (p=0.701)., Conclusion: If a thorough physical examination of a patient with RHF reveals limited forearm rotation, effort must be made to identify the cause, and the possibility of CCD must be considered. Moreover, there is a need for careful observation during RHF surgery for not only fracture reduction or fixation but also possible CCD., Level of Evidence: Level III, Therapeutic Study.