Down syndrome (DS) is a common chromosomal disorder caused by trisomy of chromosome 21 (HSA21q). Individuals with DS suffer from various congenital and progressive diseases. There is no standard treatment for DS. Due to overexpression of genes in trisomic cells, abnormal neuronal development and functional changes occur in the central nervous system of DS patients. The key deficiencies in neural stem and progenitor cell expansion lead to cognitive disabilities in DS. Human embryonic stem cells (hESCs) could serve as an expandable source for neurons production, which could be applied for the treatment of various diseases affecting the brain. In this article, we report a case of DS patient treated with hESC therapy. A DS child had delayed milestones, with no speech, subnormal understanding and subnormal motor skills. Following the treatment, patient showed remarkable changes and improvement in the clinical conditions such as better understanding, improved muscle tone of limbs and ability to recognize near ones. hESC therapy was found to be beneficial in the treatment of DS. Further studies are needed to understand the clinical utility of hESC therapy in the patients with DS.