Benign solid tumors of the fallopian tubes are extremely rare and often difficult to differentiate from tumors associated with adjacent organs or from various inflammatory diseases. Here, we present a patient who was diagnosed with ectopic pregnancy, based on preoperative tests and intraoperative macroscopic findings, but was later diagnosed with a fallopian tube adenofibroma, based on histopathological evidence, and intrauterine pregnancy. Although initial pregnancy test results were positive, no gestational sac (GS) was seen in the uterus and the patient was diagnosed with an ectopic pregnancy and underwent emergency laparoscopic surgery. A 20-mm, fetus-like solid mass was noted inside the GS-like cystic tumor of the left fallopian tube. From histopathological findings, the lesion was identified as a serous fallopian tube adenofibroma. The baby was born healthy with no problems. This case report suggests that fallopian tube adenofibroma should be considered in the differential diagnosis of suspected ectopic pregnancies.