Group A beta-hemolytic streptococcus is one of the most important infectious agents leading to both direct damage to organs, and to various cross-reactions with body antigens. One of these forms, manifested by the defeat of subcortical ganglia, is PANDAS syndrome. This paper describes the international criteria and clarifies the differences between this disorder and other forms of brain damage. Paper also describes the clinical case of PANDAS syndrome in a 7-year-old child.