Several conceptual models of Occupational Safety and Health and (OSH) performance have been proposed by researchers. However, these models are not fully exploitable by Small- and Medium-sized Enterprises' (SME) managers and entrepreneurs because they do not take into account the particular factors and the particular structure of the cause-to-effect chain of interactions characterizing all the relevant OSH factors and the safety performance of an SME, in an intervention-oriented way through a complete view of the issue. In the light of the above, this paper proposes a systemic, intervention-oriented model of safety performance specifically designed for the SMEs. The design of the model required the identification of all the OSH factors relevant for SMEs. Using a Focus group approach, these factors have been detailed into sub-factors and grouped into affinity areas. The sub-factors provide an operational definition of the factors, useful to assess the characteristics of the company and to identify possible single interventions, while the affinity areas allow an understanding of the main dimensions that a decision maker should consider in an intervention policy. Finally, using the Interpretive Structural Modeling technique, the affinity areas have been worked into a hierarchical structure, representing the cause-to-effect chain characterizing the safety performance of an SME.