Background: Surgical site infections are one of the more common major complications of elbow fracture surgery and can contribute to other adverse outcomes, prolonged hospital stays, and increased healthcare costs. Questions/purposes: We asked: (1) What are the factors associated with a surgical site infection after elbow fracture surgery? (2) When taking the subset of closed elbow fractures only, what are the factors associated with a surgical site infection? (3) What are the common organisms isolated from an elbow infection after open treatment? Methods: One thousand three hundred twenty adult patients underwent surgery for an elbow fracture between January 2002 and July 2014 and were included in our study. Forty-eight of 1320 patients (4%) had a surgical site infection develop. Thirty-four of 1113 patients with a closed fracture (3%) had a surgical site infection develop. Results: For all elbow fractures, use of plate and screw fixation (adjusted odds ratio [OR]= 2.2; 95% CI, 1.0–4.5; p = 0.041) and use of external fixation before surgery (adjusted OR = 4.7; 95% CI, 1.1–21; p = 0.035) were associated with higher infection rates. When subset analysis was performed for closed fractures, only smoking (adjusted OR = 2.2; 95% CI, 1.1–4.5; p = 0.023) was associated with higher infection rates. Staphylococcus aureus was the most common bacteria cultured (59%). Conclusions: The only modifiable risk factor for a surgical site infection after open reduction and internal fixation was cigarette smoking. Plate fixation and temporary external fixation are likely surrogates for more complex injuries, therefore no recommendations should be inferred from this association. Surgeons should counsel patients who smoke. Level of Evidence: Level IV, prognostic study.