Choriocarcinoma belongs to one extreme of molar pregnancy, the other end is hydatidiform mole. It is a fast-growing tumor that occurs in a woman’s uterus but can easily metastasize to the lungs, liver, and brain. The abnormal tumor cells start in the tissue that would normally become the placenta. Choriocarcinoma developed after a normal pregnancy in 1 in 50,000, miscarriages in 1 in 15,000, and complete mole 1 in 40. The tumor may mimic uterine fibroid, especially when it presents as a uterine mass (which is not the common presentation) posing an initial diagnostic dilemma, as seen in our patient. The patient was an 18years P0+1 whose last normal menstrual period was a year before presentation. She presented with a history of loss of 14-week conception, then followed by 11months history of abnormal scanty vaginal bleeding lasting 21-27 days monthly, the patient was found to be mildly pale but had stable vital signs, she had a uterine mass of about 22weeks size, abdominal ultrasound scan revealed uterine fibroid. In the process of investigation serum pregnancy test was done and was found to be positive, with markedly elevated serum beta hcg. We made an assessment of choriocarcinoma and we commenced her on chemotherapy, she received 4 courses but with no decline in beta HCG. She had a total abdominal hysterectomy and histology confirmed choriocarcinoma, serum beta HCG was then immediately noticed to decline, she had further chemotherapy, and the patient did well subsequently. Huge choriocarcinoma may be mistaken for uterine fibroid, hence a high index of suspicion for choriocarcinoma is important if a patient presents with a recent history of miscarriage, uterine mass, vaginal bleeding, and a positive pregnancy test.