Pulmonary rehabilitation is beneficial for patients with chronic lung disease. However, long-term maintenance has been difficult to achieve after short-term treatment. We evaluated a telephone-based maintenance program after pulmonary rehabilitation in 172 patients with chronic lung disease recruited from pulmonary rehabilitation graduates. Subjects were randomly assigned to a 12-month maintenance intervention with weekly telephone contacts and monthly supervised reinforcement sessions (n = 87) or standard care (n = 85) and followed for 24 months. Except for a slight imbalance between sexes, experimental and control groups were equivalent at baseline and showed similar improvements after rehabilitation. During the 12-month intervention, exercise tolerance (maximum treadmill workload and 6-minute walk distance) and overall health status ratings were better maintained in the experimental group together with a reduction in hospital days. There were no group differences for other measures of pulmonary function, dyspnea, self-efficacy, generic and disease-specific quality of life, and health care use. By 24 months, there were no significant group differences. Patients returned to levels close to but above prerehabilitation measures. We conclude that a maintenance program of weekly telephone calls and monthly supervised sessions produced only modest improvements in the maintenance of benefits after pulmonary rehabilitation.