BACKGROUND: Although there are a few broadly agreed on contributory factors, the multifaceted causes of capsular contracture have remained unresolved for decades. This study investigates a variety of potential risk factors that contribute to capsular contracture in primary augmentation patients. METHODS: The data used for this analysis include 5109 implants in 2560 primary augmentation patients implanted by 34 surgeons based on 5-year results from Sientra's clinical study. Patients were evaluated at annual visits where the capsular contracture Baker grade was recorded. Potential risk factors, including patient attributes, implant attributes, surgery characteristics, pocket irrigation, and postsurgery characteristics, were analyzed using frequency and multivariate models. RESULTS: A total of 265 capsular contracture events in 179 patients were reported through 5 years. The overall Kaplan-Meier rate for capsular contracture was 7.6 percent by device. The unadjusted analysis showed increased odds of capsular contracture in smooth devices, periareolar incision, subglandular placement, antibiotic and steroid pocket irrigation, recommended massage, and surgical bra (p<0.05 for all). Results from the multivariate analysis, adjusting for all variables in the model, found six factors to be independently associated with capsular contracture (i.e., implant placement, implant surface, incision site, hematoma or seroma development, device size, and surgical bra; p<0.05 for all). CONCLUSION: This analysis has provided evidence that submuscular placement and textured implants, in addition to other factors, are significant in reducing the incidence of capsular contracture.