Smith-Magenis syndrome (SMS) is characterized by distinctive facial features that progress with age, developmental delay, cognitive impairment, and behavioral abnormalities associated with molecular anomaly in 17p11.2. Treatment includes: early childhood intervention programs, special education, vocational training later in life, and speech/language, physical, and occupational, behavioral, and sensory integration therapies. We report a 14-year-old girl with mental retardation, behavioral abnormalities and facial dysmorphism, with SMS diagnosis confirmed by cytogenetic analysis and in situ hydridization (FISH).