The work–family interface can be viewed as a process in which daily fluctuations in work demands and resources influence family functioning and behavior, and vice versa. This study aimed to test the daily processes of both directions of the work–family interface through two studies. The first study consisted of 103 male and female workers from 17 Brazilian states. The participants’ ages ranged from 20 to 61 years (M = 33.68; SD = 9.13). Each participant answered a daily questionnaire over the course of 10 days, totaling 1,030 answers. The second study’s sample consisted of 101 male and female workers from 15 states in Brazil. Participants’ ages ranged from 20 to 62 years (M = 33.77; SD = 8.46). Each participant answered the daily questionnaire over the course of ten days, with the number of answers totaling 1,010. The first study showed that at the daily level, perceived work-related demands and social support at work were significantly related to family satisfaction. The second study indicated that at the daily level, perceived family demands and family social support showed significant associations with job satisfaction. Positive affect had a mediating role in these relationships, whereas the use of problem-solving coping strategies had a moderating role. Both studies also showed that the relationships identified remain significant when the variables were tested at different times: independent variables, mediating variable and moderator variable on one day, and the dependent variable on the following day. Day-to-day implications for organizations are discussed, and suggestions for a future research agenda on the work–family interface are presented.