Up-front maximal surgical effort towards cytoreduction with the primary goal of maximum tumour resection is one of the cornerstones in the multimodal management of ovarian cancer. Despite the prognostic relevance of lymph node metastasis, there is a great debate about the role of pelvic and para-aortic lymph node dissection. In early-stage ovarian cancer, lymph node dissection is required to make an accurate clinical staging according to the FIGO classification and to select adequate adjuvant therapy. The effect of lymph node dissection on progression-free survival and overall survival in patients with advanced ovarian cancer is still unknown. There has only been one randomized trial which favoured systematic lymph node dissection instead of lymph node sampling due to significantly better progression-free survival, but there was no difference in overall survival. Patients with postoperative tumour residuals are unlikely to benefit from this procedure. The German AGO has now initiated the first study in advanced ovarian cancer (LION) which compares the value of systematic lymph node dissection with no lymph node resection in patients without any visible tumour residuals. Until these data are in fact available, patients with advanced ovarian cancer should be informed in detail about the pros and cons of systematic lymph node dissection.