An 8-year-old girl had small, papular vulval lesions for six years; the lesions were yellowish with numerous surface depressions. Symptoms due to the action of mastocyte mediators were observed. A biopsy specimen showed a dense monomorphous infiltrate of the deep dermis by rounded cells with granular cytoplasm and a round or oval central nucleus. The morphology of the lesions and red-purple metachromatic staining led to the diagnosis of xanthelasmoid mastocytosis. Symptoms were controlled with hydroxyzine. Annual follow-up has shown no evidence of systemic involvement to date. Surgery should be contemplated as a future therapeutic option, in view of the location of the lesions.