Introduction: Nowadays, life satisfaction has become one of the most important necessities in human life, and low scales of it can lead to numerous problems. This study assessed the relationship between self-efficacy and life satisfaction and the mediating role of emotion dysregulation. Materials and Methods: The statistical population of this descriptive-correlation study in 2021 included adults from Mashhad, from whom 402 individuals (136 males and 266 females) were selected by the convenient sampling method. The participants fulfilled General Self-efficacy Scale (GSES), Difficulties in Emotion Regulation Scale (DERS), and Satisfaction with Life Scale (SWLS). Data analyzed using Pearson Correlation coefficient, and Route Analysis. Results: The results of Route Analysis showed that emotion dysregulation has a mediating role in the relationship between self-efficacy and life satisfaction. The model also had an eligible direct paths from self-efficacy to life satisfaction (P< 0. 01, β, = 0. 10), emotion dysregulation to life satisfaction (P< 0. 01, β, =-0. 36), self-efficacy to emotion dysregulation (P< 0. 01, β,=-0. 40), was statistically significant. So that self-efficacy and emotion dysregulation could predict life satisfaction. Also, indirect effects were examined and showed that self-efficacy positively predicts life satisfaction through emotion dysregulation (P< 0. 01, β,= 0. 14). Conclusion: It seems that self-efficacy can predict life satisfaction through the mediating role of emotion dysregulation. Therefore, awareness programs about the importance of self-efficacy and emotion regulation can be considered to increase people's life satisfaction.