Relationship satisfaction is one of the main subjects studied in the area of interpersonal relationships, and it is something very desired by people who are in romantic relationship. The general aims of this thesis were to identify predictors of relationship satisfaction and to verify the relationship between relationship satisfaction and subjective well-being. To achieve these objectives, four studies were developed. The first study investigated concepts associated with positive valence regarding the relationship and the romantic partner. In the second study, a scale used for evaluating relationship satisfaction was adapted for Brazil and a revised version of this scale was also proposed. In the third study, the mediating effect of the perception of partner s investment in the relationship between attachment and relationship satisfaction was tested. Finally, the fourth study investigated the predictive power of aspects of the romantic relationship over subjective well-being, in addition to what is explained by the sociodemographic and personality variables. The results revealed concepts frequently associated with the relationship and romantic partner schemes, which allowed finding possible predictors of relationship satisfaction. The perception of partner s unbankable symbolic investment was an important positive predictor of relationship satisfaction, fully mediating the relationship between attachment and relationship satisfaction. Relationship satisfaction was one of the main positive predictors of subjective well-being. Based on the results of the studies in this thesis, possible interventions are suggested to improve romantic relationships that, in turn, will contribute to a happier life.