Trisomy 1q is a rare condition frequently reported in association with other chromosomal abnormalities. An adult female patient had partial trisomy of the long arm of chromosome 1 (1q32.3-->qter) and partial monosomy of the short arm of chromosome 8 (8p23-->pter) of de novo origin. Clinical features in adulthood included mental retardation, short stature, long narrow face, brachycephaly, synophrys, small downward slanting palpebral fissures and long nose. Standard cytogenetic techniques in combination with fluorescence in situ hybridisation (FISH) studies were performed to determine the origin of the extra chromosomal material.