Lymph node dissection is a standard procedure for treatment of several cancers, but its role in prostate cancer (PCa) as an adjunct of radical prostatectomy is still debated and controversial. Pelvic lymph node dissection (PLND) is currently the most reliable means of diagnosis of lymph node metastases. A uniform PLND surgical template cannot be determined, but recent evidence shows that extended PLND provides more lymph nodes, increases the accuracy of detection of lymph node metastases, and affects decision making with regard to adjuvant therapy. Several nomograms have been developed to predict those who may need more extensive PLND, while sparing the rest. Importantly, no prospective data indicate that extension of PLND improves cancer control or benefits survival. A well designed prospective randomized study is needed to resolve these issues. We present a comprehensive literature review and critical discussion of the diagnostic and therapeutic role of PLND in PCa.