This explanatory sequential mixed-methods study investigates the factors influencing Thai fathers’ involvement in early childhood Childcare. In the quantitative phase ( n = 230), fathers’ involvement in Childcare was assessed using a Childcare involvement scale to identify key contributing factors. The qualitative phase ( n = 20) further elaborated on these quantitative findings through content analysis. Stepwise multiple regression analysis demonstrated that fathers’ perceived Childcare skills, division of Childcare responsibilities, and marital satisfaction explained 53% ( p < .001) of the variance in paternal involvement. The qualitative phase expanded on these findings, identifying fathers’ involvement experiences, and revealing three central themes: responsible involvement, father–child interaction, and discipline training. These results offer valuable insights for health care professionals into the support needs of Thai fathers engaged in Childcare, facilitating better strategies for encouraging active fatherhood.