This study examined the relationship between children’s participation in childcare services from birth to 3 years of age and their parents’ subjective well-being, as well as the mediating role of parenting stress. In total, 990 parents of children aged 0–3 years from Beijing were surveyed. First, independent samples t-tests after propensity score matching revealed that parents who participated in childcare services may have significantly higher overall subjective well-being and life satisfaction than those who did not participate. Second, a descriptive analysis and an analysis of variance results indicated that remote location, low quality, and high price may be the major reasons for parents’ dissatisfaction with childcare services, and a regression analysis of childcare dissatisfaction showed that high-priced childcare services had a significant negative relationship with parent’s subjective well-being. Third, the results of a mediation analysis of parenting stress revealed that childcare services have significant direct effects on parents’ subjective well-being, and a small mediating effect of parenting stress on parent’s childcare service participation and parental subjective well-being. The findings demonstrate the importance of childcare services, especially for the provision of affordable childcare to improve parents’ subjective well-being and relieving pressure on parents.