Chromosome disorders form a major category of genetic diseases. The most common autosomal disorder is trisomy 21, also known as Down syndrome, which is compatible with survival1. Down syndrome is associated with a characteristic set of facial and physical features. It occurs in all ethnic groups and geographical regions 2 . In Bangladesh, no general or regional data are available for Down syndrome. We conducted a study to see the distribution of cytogenetic pattern of Down syndrome by chromosomal analysis from peripheral blood and also to observe the clinical features.