This article presents an empirical study on childcare accessibility and the importance of access to childcare in attaining preferred employment among women with preschool-aged children in Tokyo. The age-wise childcare accessibility of this study takes into account spatial variations in the supply and demand of childcare, as well as “spatial competition,” based on spatially micro areas — blocks. The accessibility reveals a considerable geographic mismatch between childcare center supply and demand, particularly for children aged up to two years. Empirical results show that access to childcare is closely associated with a higher probability of attaining preferred employment among women with preschool-aged children. The association is remarkably strong when a woman has a very young child aged up to two years and when the childcare center is one that is desired. Adequate childcare provision, particularly for children under the age of three, helps to augment active female participation in the labor market.