Attention deficit/hyperactivity disorder (ADHD) is characterized with decreased storage time of the information related to the lack of attention and behavioral changes such as hyperactivity and anxiety with hand features. Our purpose was to investigate the possibility to use the 2D:4D ratio in clinics as an easy prediagnostic parameter. A total of 540 people (104 ADHD, 436 controls) between 7-17 years old were included in our study. Our study group revealed a statistically meaningful difference between the ADHD and their controls in 2D:4D ratio of their right hand and the 2D:4D and 4D:5D ratios of their left hand. The male ADHD subjects and controls also demonstrated significant difference in their 2D:4D, 2D:5D, 3D:4D, and 3D:5D ratios of the right hand and the 2D:4D and 2D:5D ratios of the left hand. Especially, ADHD boys had a more feminized 2D:4D left hand ratio than the controls. While, there was a significant difference in all finger ratios of the right hand and the 2D:4D and 4D:5D ratios of the left hand between the ADHD girls and their controls. Thus, the more masculine 2D:4D right hand ratio was observed in ADHD girls. Our results pointed out that the ADHD and some other child psychiatric disorders could be early diagnosed related to the anthropologic parameters. So, the treatment of these individuals could be assigned in early period. [ABSTRACT FROM AUTHOR]