This study examined the longitudinal contribution of four different childcare arrangements attended during the preschool years to social behaviors and academic achievement up to age 15 years. Children participating in a Canadian longitudinal survey with available information on childcare attendance between ages 3 and 5 years (N = 6,852) were measured on multiple social behaviors (hyperactivity/inattention, depression/anxiety, disruptive behaviors) and academic outcomes (mathematic skills, academic achievement) across both childhood and adolescence. We conducted a propensity score matching analysis to control the selection bias for childcare attendance and performed generalized estimating equation models for panel data among matched groups. Our results showed no clear social or academic long-term advantage for Canadian children of attending any childcare arrangement in comparison to children being exclusively cared for by their parents. In contrast, children attending daycare centers had higher levels of hyperactivity/inattention until the age of 15 years. Children also had lower mathematic skills if attending daycare centers or informal childcare at preschool age, but this effect dissipated from childhood to adolescence. Interestingly, children from low-income families had higher levels of depression/anxiety if being cared for at home by someone other than their parents or relatives. This finding supports the dual-risk hypothesis suggesting that children from already impoverished families and attending informal childcare in their own home are at greater risk for internalizing difficulties.