As with many other tumors, the origin and development of ovarian cancer is constituted by several molecular mechanisms, many of which are still unknown. Furthermore, data in the literature are incomplete and often contradictory, and they are mainly founded on results obtained on cell lines and not on observations based on the in vivo study of ovarian cancer. Despite this situation, the study of control mechanisms of proliferation and differentiation in normal ovarian functioning has enabled clinicians to identify certain growth factors and oncogenes which seem to have an important role in the neoplastic transformation of ovarian tissue. In this review, our aim is to summarise the most important data regarding function of growth factors and oncogene in normal and neoplastic epithelial ovarian cells.