IntroductionThere is little known about the association between non-parental care in early childhood and attention-deficit/hyperactivity disorder (ADHD) symptoms in preschoolers. Therefore, we examined the association between childcare from grandparents/babysitters during infancy/preschool and ADHD symptoms in preschoolers. MethodsUsing stratified random sampling, we developed a sample comprising 1597 parents of children aged 1.6–7 years who were enrolled in preschool in rural and urban areas of China. Parental reports of ADHD symptoms were assessed using the preschool version of the ADHD Rating scale-IV. A regression analysis was used to examine the association between childcare from grandparents/babysitters and ADHD symptoms. ResultsChildcare from grandparents during infancy was associated with ADHD symptoms in childhood (β = 1.03, P < 0.0001). Significant associations between grandparental care and ADHD symptoms were also observed in children from families with more than one child (β = 0.64, P = 0.0035) and children living in rural areas (β = -0.78, P = 0.0032). A babysitter as the primary child caregiver in preschool was especially strongly correlated with ADHD symptoms in girls (β = 7.95, P = 0.0042). Moreover, region was strong factor associated with ADHD symptoms without adjustment for the non-parental caregivers’ age and education, whereas family income was not strongly associated with ADHD symptoms. ConclusionNon-parental caregiving (i.e., from grandparents or babysitters) in early childhood was associated with more ADHD symptoms in children. Certain characteristics in children, such as female gender and the existence of siblings, were stronger moderating factors than were family income and region.