Objective: Heart failure (HF) markedly diminishes an individual's quality of life. However, little is known about how psychosocial functioning is related to heart failure physical symptom expression (e.g., chest pain or heaviness, shortness of breath) on a day-to-day basis. Methods: Fifty-eight HF patients completed daily diaries that evaluated mood, social support, coping, and physical symptoms for 2 weeks. Results: After being prewhitened for serial dependencies the data were entered into regression analyses to determine the concurrent and lagged relationships among them. Significant concurrent relationships were obtained between physical symptoms and depression, social conflict, positive and negative mood, and symptom-focused coping. Furthermore, negative mood and distraction coping predicted greater physical symptoms the next day, while action/acceptance coping predicted fewer physical symptoms the next day. Conclusion: Our data provide evidence for an association between daily psychosocial functioning and HF physical symptoms. Implications for research and clinical work with HF patients are discussed. (C) 2004 Elsevier Inc. All rights reserved.