Steatocystoma multiplex (SM) is a rare genetic disorder with an autosomal dominant pattern of inheritance. A number of literatures have been reporting the SM pedigree with missense mutation in the keratin 17 (KRT17) gene. SM is characterized by multiple asymptomatic matchhead-sized cysts with yellowish creamy fluid on axillae, chest and arms. A 50-year-old woman presented with numerous asymptomatic small bean to child palm-sized cysts on whole body for more than 40 years. Her father and son also had similar history of multiple small cysts. She was undergone surgery in a pinching-out technique with small incisions and forceps. In histopathological study, the cysts were lined by stratified squamous epithelium without granular layer and had adjacent sebaceous lobules. The result of immunohistochemical examination with cytokeratin 17 antibody was positive on the cystic walls and sebaceous glands. After the histopathological confirmation, we carried out mutation analysis of KRT17 gene using direct sequencing and found new point mutation in the exon 1 of KRT 17 gene (c. 425G>T). This patient was treated with surgical procedure and got a good cosmetic result. We here report a case of huge steatocystoma multiplex with new point mutation in the exon 1 of KRT 17 gene.