["Autism Research, EarlyView. ", "\nABSTRACT\nThe associations between the herpesviral infections and neurodevelopmental disorders, including autism and attention deficit hyperactivity disorder (ADHD), remained unclear. Using the Taiwan National Health Insurance Research Database, the present study included 27,922 children < 6 years who were exposed to herpesviral infections between 1997 and 2011, as well as 111,688 age‐ and sex‐matched children who were not exposed. All participants who developed autism and ADHD, as well as started to use ADHD medications during the follow‐up (from enrollment to the end of 2013) were identified. Human herpesvirus (HHV) subtypes were further assessed for the neurodevelopmental disorder risk. After adjusting for demographic characteristics, perinatal conditions, Charlson Comorbidity Index scores, and all‐cause clinical visits, we found that any herpesvirus infection was associated with increased risks of developing autism (hazard risk [HR]: 2.23), ADHD (1.53), and ADHD medication use (HR: 1.42). We further observed such increased risks in HHV‐1/2, HHV‐3, HHV‐4, and other HHVs, but not in HHV‐5. Finally, a herpesviral infection involving the central nervous system was markedly related to higher risks of developing autism (HR: 6.16) and ADHD medication use (1.77). Preschool children exposed to herpesvirus infection had higher subsequent risks of autism and ADHD, as well as a greater likelihood of ADHD medication use than unexposed peers. Elucidating the immunoneuro developmental mechanisms underlying herpesviral infection and neurodevelopmental disorders will require additional investigation.\n"]