Acanthosis nigricans (AN) is characterized by velvety hyperpigmented plaques, usually observed in skin folds. The different types of the condition include obesity-associated, syndromic, drug-induced, malignancy-related, and other types of AN. AN, an FGFR3 gene mutation-related disease, is associated with varying degrees of skeletal disorders. FGFR3 gene mutations are known to cause excessive inhibition of chondrocyte growth and keratinocyte proliferation, which is responsible for AN development. To our knowledge, only a small number of cases of AN with hypochondroplasia due to FGFR3 gene mutation (p.Lys650Thr) have been described in the literature. However, there are no reports of genetically confirmed AN with hypochondroplasia in Korea. Physicians should consider syndromic AN when symptoms develop at an early age or when associated skeletal anomalies are present. (Korean J Dermatol 2023;61(5):299∼302)