In this report, we summarize the clinical and psychological follow-up data over a period of 6 to 9 years of three girls with ring chromosome 15. Ring chromosome 15 in these children was associated with marked symmetrical growth retardation without obvious dysmorphism, slight mental retardation in two patients and borderline intelligence in the third. In all three performantial IQ was better developed than attention and concentration and severe verbal disability, present in the first years of life, disappeared almost completely after the age of 6 years. The present data suggest that, despite their severe growth failure, social integration and functioning may be satisfactory in r(15) patients.