The role of a regional lymphadenectomy in the surgical management of high-grade invasive bladder cancer has evolved over the last several decades. A growing body of evidence suggests that an extended lymph node dissection may provide, not only improved prognostic information, but also a clinically significant therapeutic benefit for both lymph node-positive and -negative patients undergoing radical cystectomy. The extent of the primary bladder tumor, number of lymph nodes removed and the lymph node tumor burden are important prognostic variables in patients undergoing cystectomy. In addition, the concept of lymph node density may further improve stratification of lymph node-positive patients. The historical development and contemporary rationale for an extended pelvic lymphadenectomy in patients undergoing radical cystectomy are reviewed.