Gynaecomastia is a common situation, with a proliferation of glandular component of male breast secondary to an imbalance in sexual hormones in mammary tissue. A main cause of gynaecomastia is anabolic steroids consumption. Few studies have been performed in patients with high consumption of anabolic steroids, showing a high prevalence (52%). In this article we present a case of bilateral gynaecomastia secondary to anabolic steroids intake, with a partial response to tamoxifen. In summary, a patient with sportive habits and gynaecomastia, an early suspicious diagnosis is anabolic steroid intake. After suppression of anabolic steroid intake and treatment with tamoxifen, a high remission rate can be achieved. If gynaecomastia persisted, surgery is a good option.