In 2014, the WHO published a new classification of ovarian tumors. Modifications refer to all nosological entities, touching on epithelial tumors to a greater extent. The performed studies and the accumulated experience could reveal new mechanisms for the pathogenesis of epithelial neoplasms, identify a new morphological group of seromucinous tumors, and make changes in the grading system for serous carcinomas. The paper discusses the changes made in the 2014 WHO classification of ovarian tumors, by describing their nosological entities and comparing it with the previous revision.