Initial surgical management is commonly accepted to date as paramount in the treatment of women presenting with epithelial ovarian cancer and permits the assessment of the disease (staging), the histological confirmation of disease type and grade, and the practice of maximal debulking preceding platinum-based chemotherapy. Many studies have shown that the volume of residual disease after initial surgical cytoreduction inversely correlates with survival. Thus, women with optimal debulking performed by a trained specialist have improved median survival. In this review, we will focus on the answers gleaned from clinical trials on primary and interval surgery, which prompts the question on the timing of surgery in respect to chemotherapy. Interval debulking surgery (IDS) is secondary cytoreduction following primary debulking and is carried out in between the courses of chemotherapy. The major clinical trials and the latest systematic reviews seem unable to give any definitive guidance or recommendation for clinical practice. The choice of aggressive primary cytoreduction or upfront chemotherapy followed by second line surgical cytoreduction seems among others to have to be individualized according to tumour load, prediction of its resectability, and response to chemotherapy. The role of tumour biology must also be kept in mind. Finally, concrete answers are awaited on the timing of surgery from the ongoing prospective randomized control trials (CHORUS and EORTC 55971) though preliminary data from the latter have already been presented at major meetings (IGCS 2008; SGO 2009) and ignited strong debate.