Albright hereditary osteodystrophy (AHO), also known as Martin-Albright syndrome (MAS), is a rare autosomal dominantly transmitted disease characterized by short stature, obesity, mental retardation, a round facies, and brachymetacarpia and -tarsia, as well as cutaneous calcification. The disease is caused by mutations in the GNAS gene localized on chromosome 20q13.2 encoding for an adenyl-cyclase-stimulating protein (Gsalpha). A 58-year-old patient presented with small stature since childhood, moderate mental retardation, round facies and soft tissue masses on the thighs. A biopsy of the latter showed subcutaneous ossification. Laboratory results showed hypocalcemia, as well as increased plasma levels of PTH and calcitonin. The clinical diagnosis was confirmed by detection of reduced activity of Gsalpha. In patients with cutaneous calcification and disturbed calcium metabolism, AHO is an important differential diagnostic consideration.