Sentinel lymph node dissection (SLND) is an important procedure in the staging of patients with cutaneous melanoma. As opposed to breast cancers, which may have lymphatic spread in a random manner, skin melanomas have a straightforward lymphatic flow that can be mapped. The metastases rarely skip to higher lymph nodes; therefore, an SLND can provide the first evidence of metastatic spread of the melanoma. This operation is indicated in patients who do not have palpable regional lymph nodes. The original melanoma on histologic studies following wide excision should be of intermediate or greater thickness (> 1 mm). If thinner, the melanoma should have associated high risk factors such as ulceration. Additional risk factors to be considered are age, site, Clark's level of invasion, and gender. An SNLD that uses both radionuclide and blue dye is highly accurate in finding positive lymph nodes. It allows a focused pathologic examination by the pathologist with both routine hematoxylin and eosin (H&E), plus immunohistochemical staining on the lymph nodes that are most likely to contain metastases. Finally, an SLND should be considered prior to a wide excision of the primary melanoma site. This is especially important if a rotational skin flap is planned for closure, as the resultant scar will alter the dermal lymphatic flow.