A descriptive study on 119 children with ADHD from 6 to 17 ages has been carried out in the National Hospital of Pediatrics from January to June 2012, aiming to know about some epidermiological characteristics of ADHD in Vietnamese children and hence to draw out expriences in diagnosis and treatment of the disorder. The results show that, the ADHD prevalence in this study was 70.59 percent among 69 children with hyperactivity-impulsivity categories. The significal factors found on this study consist in the distribution of ADHD among the number and age and sex of those children, the frequency more in boys than in girls (84.5 percent vs 35.5 percent), as well as the common symptoms found among them.