From an early age, children internalize gender stereotypes and roles, which can influence their preferences, aspirations, and social interactions. This study aimed to test the effectiveness of an intervention using counter-stereotypical narratives to reduce gender stereotyping and its consequences at two developmental stages: before the period of gender stereotypical rigidity (before age 5-6) and after (ages 6 and older). Across four studies--three exploratory (N1 = 101, N2 = 126, N3 = 67) and one confirmatory (N4 = 232)--results showed that the intervention effectively reduced gender stereotyping, specifically in the attribution of toys and professional roles to both genders. These effects persisted over time, as evidenced by a two-week follow-up (Study 4). Additionally, the intervention significantly decreased gender-based exclusion in play among younger children (Study 1), highlighting its early developmental impact. The findings support the utility of integrating counter-stereotypical narratives and reflective discussions into educational settings, providing educators and families with an accessible tool to foster more flexible gender schemas and encourage inclusive attitudes and behaviors from early childhood.