Purpose-The extant literature on lean service reveals a noticeable lack of theoretical models establishing the core constructs of lean service, their interrelation and impact on organizational performance. The purpose of this paper is to address this gap by proposing a theoretical model in which lean constructs are identified and operationalized to establish their interrelation and impact on organizational performance. Design/methodology/approach-This paper synthesizes information drawing on a systematic review of the literature on lean service, other relevant academic literature to develop a theoretical model and a set of propositions. Drawing on the universal theory, socio-technical systems theory and contingency theory (CT), the paper highlights and clarifies the potential impact of lean service on operational and financial performance. Findings-This study identifies a comprehensive set of lean technical practices, lean supportive practices, inhibitors and expected outcome of lean service. Expected relationships among those constructs are established by developing a conceptual framework with several propositions based on the relevant literature and the socio-technical system theory, the universal perspective and the CT, when relevant. Moreover, six influential contextual variables on the lean-performance relation are identified based on a review of the management accounting literature, organizational strategy literature and diversification literature to overcome limitations of previous studies. Originality/value-This paper covers a gap in the literature by identifying and operationalizing lean service constructs and offering a theoretical model with several propositions that establish relationships between lean constructs and overcome limitations in previous studies by identifying six contextual variables that are important factors in the lean-performance associations.