Testosterone cypionate and Stanozolol are Anabolic-Androgenic Steroids (AAS) which are synthetic substances that possess functions similar to testosterone. The use of these substances has increased considerably among youngsters and sports practitioners aiming better performance of with aesthetic purposes. The major concern is the effects caused by the inappropriate use of the substances, such as hypertension, myocardial ischemia, and left ventricle hypertrophy. The objective of the present research was to measure the diameter of the left ventricle lumen and the thickness of the left ventricle myocardium in mice submitted to supraphysiological doses of AAS. A total of 30 female Swiss mice were used in the experiments. The animals received supraphysiological doses of the AAS for 30 days, and during the treatment period, they were put to swim in intercalated days. After treatment animals were euthanized and slides were made from the hearts for measurements. Results demonstrated that both AAS changed significantly the heart morphology: Testosterone cypionate led to an increase in the ventricular lumen and stanozolol increased left ventricle myocardium thickness. In conclusion, the use of AAS in supraphysiological doses can change the heart morphology and can lead to serious health consequences.