Although there are possible cardiovascular adverse effects associated with the azithromycin treatment according to some case reports and cohort studies, there is no experimental study evaluating cardiotoxicity in repeated pharmacological doses of this drug. In our study, 15 mg/kg and 30 mg/kg azithromycin were orally administered to rats for 14 days to evaluate the cardiotoxicity of this drug. ECGs of the azithromycin-treated and control animals were recorded. Blood samples were assayed to determine LDH and CK-MB levels. Additionally, CAT, SOD, GSH and MDA levels of heart tissues were measured. According to our ECG recordings, decreased heart rate, prolonged PR and QT intervals, QRS complex and T wave abnormalities were observed in 30 mg/kg azithromycin-administered group significantly when compared with control group. Plasma CK-MB and LDH levels were increased in 30 mg/kg azithromycin-administered group significantly when compared to the control group. In heart tissues, CAT, SOD and GSH levels were decreased while MDA levels were increased in both azithromycin-administered groups significantly when compared with the control group. In conclusion, our findings supported the possible cardiotoxicity risk with azithromycin treatment and also, oxidative stress, which was induced by azithromycin in our study, was thought to be occurred secondary to cardiac toxicity of the drug.