Terrible triad injuries of the elbow, consisting of posterior ulnohumeral joint dislocation with associated fractures of the radial head and coronoid process, are challenging injuries due to the difficulty in restoring stability to the joint surgically while also attempting to allow early ROM to prevent stiffness. Furthermore, complications are both debilitating and relatively common, frequently requiring reoperation. (1) What patient-, injury-, or surgery-related factors are associated with reoperation after surgical treatment of terrible triad injuries of the elbow? (2) What are the most common causes of reoperation after these injuries? Between January 2000 and June 2017, we identified 114 patients who had surgery for terrible triad injuries at two tertiary-care referral centers. Of those, 40% (46 of 114) were lost to follow-up before 1 year, and an additional 5% (6 of 114) were excluded because they underwent the index surgery at an outside institution (n = 4) or underwent closed reduction with or without percutaneous pinning (n = 2). That left 62 patients for analysis in this retrospective study with a minimum of 1-year follow-up (median 22 months; range 12 to 65) or who met the endpoint of reoperation before 1 year. During the study period, indications for surgical treatment of terrible triad injuries of the elbow included joint incongruity or instability precluding early ROM. In our study cohort, 45% (28 of 62) underwent reoperation. Indications for reoperation after surgical treatment included stiffness that interfered with activities of daily life, symptomatic prominent hardware, ulnar neuropathy, instability of the elbow joint at rest or with range of motion, and infection. Patient-related (such as age, sex, race), injury-related (for example, ipsilateral extremity fracture, open fracture), and surgery-related factors (for instance, time to surgery, radial head treatment) as well as outcomes were collected by the treating surgeon at the time of follow-up and ascertained using chart review. The primary outcome measure was reoperation after surgical treatment of a terrible triad injury of the elbow. Bivariate analysis was used to assess whether explanatory variables were associated with reoperation after surgical treatment of terrible triad injuries of the elbow. Of the patient-, injury-, and surgery-related factors that were analyzed, only radial head treatment was associated with an increased reoperation risk (p = 0.03). No other variable met criteria for inclusion in our multivariable logistic regression model (p < 0.10), and therefore, a multivariable logistic regression model was not performed. The most common indication for reoperation was stiffness (21% [13 of 62 patients]), followed by symptomatic hardware (18% [11 of 62 patients]), nerve symptoms (ulnar neuropathy 16% [10 of 62 patients] and incisional neuroma 2% [1 of 62 patients]), instability (6% [4 of 62 patients]), and wound problems (infection 2% [1 of 62 patients]). The reoperation risk after surgical treatment of terrible triad injuries of the elbow is high. No patient- or injury-related factors were associated with the reoperation risk. Based on our finding, we recommend fixation of radial head fractures in these injuries when feasible and compatible with early postoperative motion, and we suggest the use of radial head excision or arthroplasty as a secondary options. Level III, therapeutic study.