Primary fallopian tube carcinoma is rare and accounts for about 0.3% of all gynaecolgical cancers. Fewer than 2000 cases have been reported in literature. In routine practice, a case of tubal carcinoma is usually diagnosed as an adenxal mass, more commonly as an ovarian tumour. It is usually an intraoperative finding or a histopathological diagnosis. A 45 year old postmenopausal woman, presented with the complaint of pain abdomen since 3 months. On per vaginal examination her uterus was retroverted, 10 to 12 weeks in size and a hard, fixed, nontender, irregular mass of 8 cm x 8 cm, in continuation with the uterus was felt in the left fornix. The clinical and radiological findings with an elevated CA 125 suggested an ovarian tumour with a fibroid uterus. An exploratory laprotomy was done and in the left fallopian tube an exophytic growth 10 cm x 10 cm adherent to the lateral pelvic wall was detected. The left ovary was seen seperate from the mass. Histopathology report confirmed it as a papillary serous adenocarcinoma of the fallopian tube.