Following a brief overview of the stressful life events-illness model and its implications for intervention, this article highlights the role of social support as a resource for resisting stress-induced illness and disability. It identifies three different connotative meanings that have been assigned to the social support construct, and describes their empirical operationalizations in several recent studies. Specifically, the social integration/participation formulation, the social network approach, and the social intimacy measurement strategy are described and contrasted. Within the latter approach, one study that illuminated types of informal helping behaviors is discussed in greater detail. A review of possible mechanisms whereby social support accomplishes its health-protective impact is also offered, and two types of planned interventions involving the mobilization or optimization of social support are spotlighted. The article concludes with ideas about ways that professionals can safeguard the natural helping skills of citizens and achieve an appropriate balance between formal and informal systems of service delivery in the health and human services fields.