A female's risk at birth of having ovarian tumor sometime in her life is 6-7%. Relative frequency of ovarian tumor is different for western and Asian countries. Two third of ovarian tumors occur in women of reproductive age group. This study was done in Tribhuvan University Teaching Hospital with aim to find out frequency of different histological types of ovarian tumors and their age distribution and thus provide an institutional experience from Nepal also. One hundred and sixty one ovarian tumors, reported from April 2004 to March 2006 were included in the study. One hundred and thirty five of these tumors (83.9%) were benign and 16.1% (26/161) were malignant. Surface epithelial tumors were most common (52.2%) followed by germ cell tumors (42.2%). Mature cystic teratoma was commonest benign tumor (48.2%). Serous adenocarcinoma was commonest malignant tumor (46.2%). For all age groups, benign tumors were more common than malignant ones. Most ovarian tumors (47.2%) were seen between 21 -40 years where as most malignant tumors (73.1%) were seen above 40 years. In 1st two decades, germ cell tumors were more common than other tumors.