This study tested Self-Determination Theory as a possible explanatory framework to understand the relationship between total couple leisure satisfaction and marital satisfaction. The three psychological needs of autonomy, competence, and relatedness—fundamental components of Self-Determination Theory—were measured through the Fulfillment of Psychological Needs during Couple Leisure (FPNL) scale and were tested as mediators. The analysis of five structural equation models confirmed the relevance of the Self-Determination Theory in explaining the relationship between couple leisure satisfaction and marital satisfaction. Although autonomy and competence were significant mediators, relatedness consistently appeared as the strongest mediator suggesting that the fulfillment of this psychological need is particularly important for relationship functioning and well-being. Implications to couple leisure are discussed.