Heterotopic pregnancy refers to simultaneous presence of intrauterine and ectopic gestational sacs. Its incidence exhibits a rising trend due to the increased use of assisted reproductive technology (ART). This paper aims to present a rare case of tubal and cesarean scar heterotopic pregnancy that occurred following a spontaneous pregnancy. The patient presenting with delayed menstruation and abdominal-inguinal pain was evaluated. Transvaginal ultrasonography revealed a gestational sac located in the scar of a previous cesarean section and in the left tubal region corresponding to a gestational age of 4 weeks and 5 days. The patient was hospitalized and informed about conservative and surgical methods. Then, she was administered a single dose of methotrexate 75 mg intramuscularly. Post-operative period included ultrasonographic and laboratory follow-up. In conclusion, it should be remembered that single-dose systemic methotrexate therapy might constitute an alternative to surgery in unruptured hemodynamically stable cases.