Abstract The ring 14 chromosome is a rare chromosomal aberration characterized by a distinct phenotype consisting of dysmorphic features including mental retardation, epileptic seizures, ocular anomalies, microcephaly, pre-mature birth, late birth cry, skin pigmentation, short neck and low set ears. Cytogenetic evaluation was done on 17 years boy who was discovered to have previously undescribed chromosomal abnormality 42, XY, 14(r), -14 +Marker/ 44, XY. The parents had the normal karyotypes that indicate de novo origin of this abnormality. Stanford - Binet test was performed to assess the degree of severity of mental retardation and was found to be mild (IQ: 50-55 to 70). To our knowledge this is the first report evaluated with ring (14) mosaicism. Literature of published cases is reviewed in this article but none of these reports pertain mosaicism of this type.