Background: Trigger finger release (TFR) is one of the most commonly performed hand procedures and typically results in restoration of normal finger function. However, uncommon postoperative complications such as deep infection can have devastating consequences. The goal of this study was to evaluate the incidence, risk factors, and characteristics of infectious flexor tenosynovitis occurring after TFR. Methods: We searched billing records for the Current Procedural Terminology code for TFR to identify all adult patients who underwent TFR at our institution over a 10-year period. We defined infectious tenosynovitis as any case where the patient underwent tendon sheath drainage or postoperative wound debridement within 6 months of the index TFR procedure. Medical records were reviewed to obtain patient demographic information, body mass index (BMI), tobacco use, history of diabetes mellitus, surgical setting (clinic vs outpatient surgery center), and surgical digit for all patients. In those patients treated for infection, we recorded hospital length of stay, number of operative procedures, and any culture results. Results: We identified a total of 18 infections out of 2307 procedures (1827 patients), for an incidence of 0.99%. Current smokers had a significantly higher incidence of infection than nonsmokers (1.77% vs 0.29%). On univariate analysis, smoking was closely associated with infection (P ≤ .05). All infections occurred in overweight or obese patients by BMI criteria, but there was no difference in average BMI between patients with and without infection. History of diabetes, in-office surgery, patient age, and patient sex were not associated with a higher incidence of infection. Patients with infections spent an average of 4.1 days in the hospital, and 40% required multiple surgical procedures. The most common infectious organism cultured was Staphylococcus aureus, which was present in 67% of infections. Patients with isolated methicillin-sensitive S aureus on culture showed signs of infection within 3 weeks of the index procedure, whereas polymicrobial, coagulase-negative staphylococci or beta hemolytic streptococci were identified in patients presenting with infectious symptoms later. Conclusion: Infections after TFR are uncommon but are more likely to occur in patients who are current smokers and overweight or obese by BMI criteria. Methicillin-sensitive S aureus is the most likely causative organism, especially in patients presenting during the early postoperative course.