Abdominal ectopic pregnancy has been reported to occur in approximately 1% of overall patients diagnosed with ectopic pregnancy. Definite diagnosis of abdominal pregnancy by using image study is limited. Early diagnosis is often delayed, which result in high maternal morbidity and mortality due to massive bleeding. Therefore, diagnostic surgical intervention should be generally considered as a first-line if there is any sign suspected for abdominal ectopic pregnancy. Uterine serosal pregnancy is extremely rare form of abdominal ectopic pregnancy. Exact mechanism of uterine serosal pregnancy is also not well defined, and only few cases were reported so far. Here, we report a case of 35-year-old primigravidarum who diagnosed with uterine serosal pregnancy via laparoscopic intervention. The patient was referred from local clinic for ruptured left tubal pregnancy at amenorrhea 5+0 weeks with elevated serum beta human chorionic gonadotropin (b-hCG) level (16,618mIU/mL). Transvaginal sonography revealed 1.8 cm sized mass located adjacent to the left cornus with certain amount of hemoperitoneum. With the preoperative impression of left cornual pregnancy with ruptured status, the patient was underwent emergent diagnostic laparoscopy. Entering the abdominal cavity, about 300 mL hemoperitoneum was noted, and 2x2cm-sized ruptured ectopic mass was dangling from the left posterior wall of uterine serosa, causing active bleeding. Both adnexae and other pelvic organ were grossly normal. The ectopic mass was successfully removed and the uterine scar was meticulous sutured. The pathologic reports confirmed the ectopic pregnancy. The patient's postoperative course was uneventful and the level of serum b-hCG gradually decreased within normal range. (1429 mIU/mL at POD 7, 79.47 mIU/mL at POD 14, and 4.87 mIU/mL at POD 28.