Backgrounds: Turner syndrome (TS) also called monosomy X or Ulrich, is a congenital disorder caused by one intact X chromosome and the absence of second sex chromosomes. Only females are affected by Turner syndrome, characterized by abnormalities affecting the X chromosomes. Its incidence about 2.5-5.5 per 10,000 live births of girls. Mosaic 47, XXX karyotype is found in 3%-4% of TS patients. Objective: To describe clinical manifestation and examination aspects of mosaicism turner syndrome. Case presentation: An 18-years-old girl came with complaint short stature. This complaint has been noticed since the patient was in elementary school. The patient's parents initiated to have their child checked by pediatric endocrinologist when the patient was 6 years old. The patient was diagnosed with Turner syndrome from the result of chromosomal examination. The patient was given growth hormone by pediatrician with unknown dosage for approximately 1.5 years but the patient has never returned to control. During that period of time, her breast developed when she was 11 years old and the patient had menstruation at the age of 14 but the menstrual cycle was irregular. Physical examination showed the patient with short stature, low hairline, shield-shaped chest and right elbow deformity. The Sexual Maturity Rating score was M4P4. Her anthropometric status was overweight and short stature with height for age < P3rd. The patient's bone age was equivalent with child age 17-years-old. Karyotype examination with G-banding technique, the chromosomes from 40 cells have been studied and the number of chromosomes in each cell studied is mos 47, XXX[30]/45, X[10]. Ultrasonography examination showed the uterus anteflexed below normal size, the right ovary appears below normal size, and the left ovary is not visible. Conclusion: An 18-year-old girl with mosaic Turner syndrome. The diagnosis is established by history taking, physical examination, hormone examination, imaging and karyotyping. Patient was treated with growth hormone.