Objectives: This study was conducted to verify the mediating effect of couples’ emotional interactions in the relationship between perceived stress and life satisfaction of the elderly. Methods: For this study, a survey was conducted on 300 senior citizens aged 65 or older who visited welfare centers and public institutions, excluding 35 unfaithfully prepared questionnaires, with 265 surveys verified using a three-stage mediated regression analysis by Baron and Kenny (1986). Results: First, positive emotional interactions between couples in the relationship between perceived stress and life satisfaction were found to have partial mediated effects. Second, the couples’ negative emotional interactions were also found to have a partial mediating effect of reducing the negative influence of perceived stress on life satisfaction. Third, it has been confirmed that self-acceptance also has a partial mediating effect in the relationship between perceived stress and life satisfaction. Conclusions: Couples’ positive emotional interactions, negative emotional interactions, and self-acceptance were presented as useful psychological and relational mechanisms to reduce the negative influence of perceived stress on the satisfaction of life of the elderly.