Researchers have investigated the external elements that can condition a person's satisfaction with life, although it has been proven that they do not explain a large part of the phenomenon. For this reason, other variables such as perceived competence, personality styles and personal autonomy are being investigated more successfully. The main objective of this paper is to study the influence of parental educational practices on adolescent life satisfaction considering the role played by adolescent's positive affect and the agreeableness personality trait by implementing a statistical Mediation Model that explains such relationship. The population sample is a total of 742 Spanish adolescents, of which 45.1% were boys and 51.5% were girls. The age ranged between 13 and 19 years (15.63, SD = 1.24). The results revealed that the relationship between parental educational practices and life satisfaction in adolescence was mediated by positive affect and the personality trait of agreeableness. Both variables did act as serial mediators in this relationship. On the other hand, the serial multiple mediation structural model explained 31.72% of the variability in life satisfaction for the dimension of affection and communication and promotion of autonomy, 29.70% for the psychological control dimension, 26.58% for self-disclosure and 28.21% for the humor dimension of parental educational practices. These findings have important implications to understand the relationship between parental educational practices and the adolescent life satisfaction, indicating that different parental educational practices will have a positive or negative effect on adolescent positive affect, which will lead to increased or decreased agreeableness influencing the adolescent life satisfaction.