As in other countries, Portugal has gone through great social, political and economic changes, with women massively entering the workforce, and having one of the highest percentages of double-income families, with small children (Eurofound, 2017). With fathers no longer being the sole economical providers, the notion of a more active (shared) role in family life, and particularly in childcare and education emerges (Pleck, 2010), with the increase of family-oriented policies (e.g., Wall & Leitão, 2015). This study aimed to assess the balance (gains & strains) between family and work from father’s perspectives, in dual-earners families, with small children. Considering father’s, as well as mother’s, education and working status/hours, we tested if of father’s involvement in child related activities (care and socialization) occurring in families daily routines, would influence father’s balance of work and family – gains and strains. Interactions between father involvement and his working hours were tested. Method: Participants were 170 Portuguese dual-earners couples with children attending preschool (M = 53.45; SD = 10.38 months old). Fathers’ education ranged from primary school to a university degree (M = 12.82; SD = 4.10) and worked on average 40.97 hours (SD = 5.27) a week. Mothers’ education ranged from primary school to a university degree (M = 14.47; SD = 3.65) and worked on average 38.54 hours (SD = 5.17) a week. Instruments/Procedure: Fathers completed the “Combining Work and Family” (NICHD, 1991; Martins et al., 2008) with three dimensions: Gains/Benefits from work and family; Strains from work and family; and a global score associated with the Stress derived from balancing these two systems. Both mothers and fathers independently completed the “Parental Involvement Questionnaire: Child Care and Socialization Activities” (Monteiro et al., 2008) to assess father’s relative involvement to the mother (direct care; indirect care; play; teaching/discipline). A composite measure was computed by averaging both parents’ reports. Results: A multiple hierarchical regression was conducted in two blocks (mother and father’s education and working hours, and father’s involvement domains) for father’s Gains, Strains and Stress associated with the balance between work and family (Table 1). For Gains (F(12, 158) = 1.13, p = .34) and Stress (F(12, 158) = 1.46, p = .15) dimensions, the models did not reach significance. Whereas for Strains (F(12, 158) = 2.81, p = .00), not only the regression model proved to be significant, but father’s involvement in indirect care (b = -.26, p = .01) and play activities (b = -.20, p = .03) were found to be significant predictors. Furthermore, a significant interaction was found between father’s working hours and his involvement in teaching/discipline activities (b = .34, p = .02). Results will be discussed considering the challenge for fathers in dual-earner families with small children, to balance work and family. The role of fathers’ involvement and its implications to the facilitation and/or constraints will be discussed.