The purpose of this study was to describe the complications of immediate breast reconstruction, to compare their rates with respect to the surgical procedure and to patient's characteristics, in order to improve surgical indications and patient information. We carried out a retrospective study of 266 immediate breast reconstructions (249 women) over a 12-year period (latissimus dorsi myocutaneous flap with implant 61%, autologous latissimus dorsi myocutaneous flap 15%, subpectoral implant 24%). Mean age was 48 and the median follow-up was seven years (2-14). The overall complication rate was 49% (128), and there were 10 reconstruction failures. The most frequent complications were dorsal seroma 26% (70), capsular contracture 10% (27), skin necrosis 8.3% (22), and haematoma 5.6% (15). The complication rate for immediate breast reconstruction with implant alone (39%) was lower than that associated with latissimus dorsi with or without implant (51%), but the difference was not significant (Chi-square: p=0.07). The risk factors for complications were smoking (skin necrosis, Fisher: p=0.02), obesity (infection, Fisher: p=0.004), and radiotherapy (capsular contracture, Chi-square: p=2.6 x 10(-5)). Smoking was found as the only risk factor of reconstruction failure (Fisher: p=0.015). Capsular contractures were more frequent when implants were used alone (25%) as well as when used along with a flap (6.8%) (Chi-square: p=2 x 10(-5)). Infections were also higher in the non-flap group than in the flap group (Fisher: p=0.02). In our opinion, latissimus dorsi myocutaneous flap with or without an implant is a good compromise between complication risk and necessity of good cosmetic result requirement. These results have led us to delay or contraindicate reconstruction in the case of obesity or heavy smoking. In the case of probable post-operative radiotherapy, we prefer to delay the breast reconstruction.