Monosomy 1p36 Syndrome is a well known, rare genetic disorder caused by the deletion in the distal part of the short arm of chromosome 1, in which prenatal and postnatal growth and mental retardation is usually accompanied by psychomotor retardation, late-closed large fontanels and typical fascial findings. Herein, a 16-year-old female subject considered to be Monosomy 1p36 Syndrome is presented. A deletion was determined in 1p36 region after high resolution banding (HRB) technique. This deletion determined with conventional cytogenetic analysis was confirmed using fluorescence in situ hybridization (FISH) technique [46,XX.ish del(1)(p36)dn]. This presentation emphasizes the importance of clinical diagnosis in Monosomy 1p36 Syndrome and the value of conventional methods and FISH technique in diagnosing this syndrome.