BACKGROUND: Capsular contracture is the most frequent complication after primary augmentation mammoplasty. The practice of irrigating implant pockets with a triple antibiotic solution has been widely adopted in an attempt to prevent capsular contracture, despite a limited understanding of the inciting pathophysiology. Capsular contracture is commonly attributed to subclinical infection, immunologic response to breast implants, and chronic inflammatory changes caused by the presence of the implants. The purpose of this study was to evaluate if antibiotic irrigation was superior to saline in reducing the long-term incidence and severity of capsular contracture after primary augmentation mammoplasty. METHODS: A retrospective cohort study enrolling patients having undergone primary augmentation mammoplasty by the authors between 2011 and 2012 for all women satisfying inclusion and exclusion criteria was conducted using prospectively collected quality assurance data. Surgical technique between surgeons was controlled such that the only difference was the use of antibiotic irrigation in the treatment group. Analysis with predetermined 95% confidence intervals was performed using χ test and analysis of variance. RESULTS: Fifty-five patients underwent surgery. Twenty-eight patients treated with saline (control) were included, ranging in age from 22 to 50 years with a mean follow-up time of 2.8 years. Twenty-seven patients were treated with triple antibiotic solution (treatment) ranging in age from 22 to 56 years with a mean follow-up time of 2.6 years. Rates of capsular contracture were 3.6% (control group) and 3.7% (treatment group). χ statistic was found to be 0.0014 (P = 0.97) and analysis of variance F value was 1 (P = 0.39). CONCLUSIONS: There was no difference between triple antibiotic and saline irrigation in the incidence or severity of capsular contracture at 2.8 years follow-up when high-quality surgical technique is used.