The aim of this study was to explore the relationship between Organizational Commitment and Life Satisfaction, as well as to determine if employee engagement act as a facilitator. It was proposed that affective and normative dimensions of commitment would be significantly related to life satisfaction through the mediation of engagement. To test this preposition data were collected from a sample of 305 Spanish employees; data were analyzed with structural equation modeling (SEM) techniques, finding that the affective dimension of commitment is the most associated with life satisfaction. This relationship is mediated by employee engagement, specifically by the vigor or energy experienced at work.