Schimmelpenning syndrome, or epidermal nevus syndrome, is a rare, neurocutaneous disorder characterized by skin abnormalities, such as epidermal nevi, and involvement of the central nervous system, including intracranial tumors. There are only a few reported cases of intracranial tumors associated with Schimmelpenning syndrome. In most cases, a single nucleotide mutation in the RAS family proto-oncogenes, like HRAS or KRAS genes, can result in the genetic mosaicism that is responsible for the clinical manifestations of this syndrome. The authors present a case report of a woman with Schimmelpenning syndrome who sought medical help with complaints of progressive headache and dizziness. The radiological and histopathological findings indicated an astrocytoma, IDH-mutant (WHO grade 3). The molecular analysis revealed pathogenic changes in the oncogenic HRAS gene with a prevalence of 31%. The patient underwent surgical treatment and had no neurological sequelae. By presenting such a clinical case, attention is paid to the interrelationship between genetic syndromes and intracranial tumors.