Introduction. Endometriosis is one of the most common benign disorders which affects 10-15% of all women in reproductive age. The association between endometriosis and ovarian cancer has been frequently described in the medical literature. Purpose. To evaluate the literature for evidence of a correlation between endometriosis and ovarian cancer. Method. the English language literature (online MEDLINE and EMBASE database) was searched using the keywords endometriosis combined with cancer, tumour, tumor, carcinoma, or adenocarcinoma. All abstracts between January 1985 and August 2010 were reviewed. Full relevant articles were critically assessed. Reference lists of included studies were checked. Results. Seven out of the eight studies, included in our review, have shown an increased risk of ovarian cancer. However, the effect size is modest (OR, RR, and SIR) ranging between 1.32 and 1.9 (95% CI). A causative relationship between the two incidences cannot be confirmed. There is increasing evidence on the role of genetic mutations in ovarian clear-cell and endometrioid carcinoma developing from endometriosis. Conclusion. More evidence is needed before suggesting any change in the current management of endometriosis.