Social support is a concept of particular interest to nursing because of its influence on clients' physical and mental well-being. A qualitative study exploring parents' experiences when their children were hospitalized for the treatment of cancer provided the opportunity to explore the informal relationships parents established with parents of other children also hospitalized with cancer. As 27 parents of 24 children participated in extensive interviews it became clear that the relationships established with other parents were generally perceived as supportive. Analysis and interpretation of the data identify characteristics and foci of interactions perceived as supportive. In addition, conditions related to the diagnosis of cancer and the hospitalization experience that acted to enhance and detract from the supportiveness of the relationships are also noted. Findings are analyzed in relation to the current literature on social support. Implications for nursing are identified.