In this study we report a female patient with an interstitial duplication of a region (10q22-q23) which is rarely reported in the literature. We fine mapped the aberration with array CGH, which revealed an 18.6-Mb duplication, covering 89 annotated genes, at 10q22.2-q23.33. There were no other deletions or duplications elsewhere in the genome. The main clinical features of the patient are microcephaly and congenital heart disease, which are likely to be caused by dosage effect of one or several genes in the duplicated region. Similar phenotypes have been found in other patients with 10q11-q22 duplications and in two out of three patients with 10q22-q25 duplications. However, most of the duplication cases were investigated only by conventional chromosome analyses, and fine mapping of these and other duplications of 10q22-q23 are warranted for genotype-phenotype comparisons.