Gamma probe-guided lymphadenectomy of prostate cancer that is presumed to be localized furnishes evidence that lymphogenous spread of the disease is present considerably more often and earlier than previously assumed, even when the clinical stage is considered localized. Multiinstitutional trials have confirmed that in principle sentinel lymphadenectomy on its own is able to detect lymph node positive patients with minimal complications and a sufficient degree of certainty. Sentinel lymphadenectomy for penile cancer is an undemanding surgical procedure and in contrast to inguinal lymphadenectomy can be considered minimally invasive. Decisions on indication and necessity for an additional inguinal lymphadenectomy depending on tumor stage and local findings in the inguinal lymph nodes are handled quite differently in various centers and should be further standardized. The most recent studies on sentinel lymphadenectomy for urinary bladder and testicular cancer demonstrate that on principle the procedure is likely feasible also for these tumor entities. Whether it is possible to replace standard treatment methods with these procedures or at least have them serve an ancillary function remains to be determined in further investigations. Basically, the premise holds true that for all urological tumor entities before standard diagnostic techniques are abandoned, the value of exclusively performing sentinel lymphadenectomy must be adequately validated. It does not suffice to rely on the results from other working groups. It is in fact essential that the accuracy of the method - the feasibility of which can be influenced by numerous factors - be assessed by comparison with a standard lymphadenectomy performed in one's own center.