We report a case of segmental lentiginosis (unilateral lentiginosis), that is, asymmetric distribution of lentigines on one side of the body, in a 23-year-old woman. Lesions involved the right side of the face and the cervical region, mostly within the area of division of the trigeminal nerve. Histologic examination disclosed a lentiginous pattern as well as some nests of melanocytes at the dermal-epidermal junction (so-called jentigo pattern). Similar cases have been described in the literature under the term "zosteriform lentiginous nevus," which in our opinion makes for confusion since the same term has also been used to describe cases that fit the diagnostic criteria for speckled lentiginous nevus (nevus spilus).