McCune-Albright syndrome (MAS) is a very rare disease characterized by the triad of bone defects, skin hyperpigmentation, and various types of endocrine and non-endocrine manifestations. It falls into the category of sporadic genetic disorders and its exact incidence is unknown. In its more severe forms, the disease manifests itself already in early childhood and can gradually affect more and more organs throughout life. The extent and degree of involvement of affected tissues are heterogeneous due to the mosaicism of the genetic mutation. The disease is the subject of extensive research and new pathogenetic mechanisms are being elucidated, leading to new diagnostic and therapeutic choices. In addition, the authors present a case report of an adult female patient with McCune-Albright syndrome. The clinical picture is dominated by bone involvement, thyroid hyperfunction and persistent hyperestrogenism. The case report underlines the fact that management of patients with McCune-Albright syndrome continues to be a challenge.