We report on a 12 year-old girl with severe myopia, ectopia lentis, dilatation of the ascending aorta, protrusio acetabulae, arachnodactyly, scoliosis and moderate short stature (-1.7 SD). Her sister and father presented with Marfan's syndrome. Despite short stature, Marfan's syndrome could not be ruled out. Primary amenorrhoea and growth retardation indicated cytogenetic analysis which showed chromosomal aberration 45,X in every studied cell. However, she did not present any other clinical features of Turner's syndrome. We report here for the first time on an association of Turner's syndrome and Marfan's syndrome in the same patient, and discuss particular clinical features.