Streptococcal infection in children is usually benign and self-limited. In a small percentage of children, prominent neurologic and/or psychiatric sequelae can occur. Sydenham chorea is the best defined and best recognized. PANDAS (pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection) is a well-defined syndrome in which tics (motor and/or vocal) and/or obsessive-compulsive disorder consistently exacerbate in temporal correlation to a group A beta-hemolytic streptococcal infection. PANDAS constitutes a subset of children with tics, Tourette syndrome, and obsessive-compulsive disorder. In addition to strictly defined PANDAS, we and others have recognized several PANDAS variants, including adult-onset variant, a dystonic variant, a myoclonic variant, and a "chronic" PANDAS variant. The nosology and classification of these entities are rapidly evolving. The recognition that some pediatric neurobehavioral syndromes have infectious and/or immunologic triggers points to important new avenues of disease treatment. In this review, we summarize this complex and rapidly evolving area of clinical research.