Many pediatric cancer patients and their parents experience serious psychosocial problems during and long after completing treatment. Designing interventions to significantly reduce these problems requires understanding their origins. Thus, our primary objective is to identify specific factors that directly and indirectly affect psychosocial adjustment. Previous research shows: (a) both parents' and children's long-term psychosocial outcomes are rooted in the treatment experience; (b) invasive treatment procedures during clinic visits (e.g., lumbar punctures) are one of the most stressful aspects of pediatric cancer; and thus (c) negative responses to these procedures (e.g., distress) place parents and children at greater risk for subsequent psychosocial problems. We have found that variability in children's immediate responses to treatment procedures is associated with variability in situational resources (i.e., resources on days of clinic visits) and in parent-child communication patterns during clinic visits. Our model of causes of psychosocial problems associated with pediatric cancer is based on these and other empirical findings. It posits that: (a) stable family resources (i.e., social, personal, and fiscal/material resources) directly affect parents' and children's psychosocial well-being; (b) stable and situational family resources affect parent-child communication during clinic visits; and (c) parent-child communication affects their responses to procedures and subsequent psychosocial adjustment. Our first aim (Phase 1) is to replicate and extend prior research on relationships among the variables in the model and to determine the viability of the overall model. Our second aim (Phase 2) is to experimentally test causal relationships between specific variables in the model and parents' and children's responses to procedures. We will conduct two separate experiments that manipulate specific situational resources and parent communication behavior and examine the direct and/or indirect effects on immediate responses to treatment procedures and on subsequent psychosocial adjustment. Phase 1 will enroll 130-150 total families of recently diagnosed pediatric cancer patients at two institutions. Families' stable resources and situational resources on days of clinic visits will be assessed. Parent-child interactions during three clinic visits will be video recorded and responses to treatment procedures will be assessed. Children's and parents' psychosocial adjustment will be assessed three, six, and nine months after completion of video-recorded clinic visits. In Phase 2, 130-150 families from the two institutions will be randomly assigned to control and experimental treatment conditions. Experimental groups will receive the manipulations. Control groups will receive standard of care. Families will be assessed in the same manner as in Phase 1.