Pregnancy implanted in a cesarean scar is rare, and is a life-threatening condition due to high risk of uterine rupture, hemorrhage, hysterectomy, and maternal mortality.We describe a 26-year-old woman who presented with five weeks of amenorrhea and a serum hCG level of 10,440 mIU/ml. Transvaginal sonography revealed a gestational sac of 15 x 11 mm containing a yolk sac located in a previous cesarean scar. She was successfully treated conservatively with multi-dose methotrexate. No side-effects were encountered. The serum hCG levels were undetectable in 58 days. The patient had normal menstrual cycles afterwards.In the view of increasing cesarean rates, healthcare professionals should be aware of the possibility of a scar pregnancy and the potentially life threatening sequelae. Early diagnosis by transvaginal sonography can improve outcome and minimize the need for emergent surgery. Conservative treatment with systemic methotrexate is an effective option in selected patients.