Enhancing daily functioning and well-being is an increasingly advocated goal in the treatment of patients with chronic disease. The authors evaluated the functioning and well-being of 9,385 adults at the time of office visits to 362 physicians in three U.S. cities, using brief surveys completed by both patients and physicians. For eight of nine common chronic medical conditions, patients with the condition showed markedly worse physical, role, and social functioning; mental health; health perceptions; and/or bodily pain compared with patients with no chronic conditions. Each condition had a unique profile among the various health components. Hypertension had the least overall impact; heart disease and patient-reported gastrointestinal disorders had the greatest impact. Patients with multiple conditions showed greater decrements in functioning and well-being than those with only one condition. Substantial variations in functioning and well-being within each chronic condition group remain to be explained.