a b s t r a c tBased upon the revised Job Demands and Resources Model (2008) we aim first, to test the relations between work-family conflict and emotional exhaustion across time and second, to determine the role of professional self-efficacy in this relation. A longitudinal study was conducted in two times, with a year of interval in a Spanish Army sample (n = 242). To test the causal relations between work-family and emotional exhaustion three models are tested: normal causal, reversed causal, and causal reciprocal. To test the role of professional self-efficacy in the relation between work-family conflict and emotional exhaustion four alternative models are tested: independence, antecedent, mediation, and independence plus antecedent models. Structural Equation Modeling results confirm the simultaneous reciprocal effects model as it fits the data better than the normal causal or the reverse causal models. This result suggests a spiral process, where work-family conflict predicts emotional exhaustion and at the same time emotional exhaustion increases work-family conflict. Likewise, this article contributes to clarifying the role of selfefficacy in the complex relationship between work-family conflict and emotional exhaustion.