The benefit of pulmonary rehabilitation is well documented for patients with chronic obstructive pulmonary disease (COPD). However, such benefit has not been demonstrated for severely impaired patients with other chronic pulmonary diseases. Occasional non-COPD patients have been admitted to our 4-wk inpatient program. We compared the improvement of these non-COPD patients with that of COPD patients in the same program. Improvement is assessed by a 6-min walk test done at admission and discharge. On the admission 6-min walk test, 32 non-COPD patients had an ambulation distance of 276 +/- 219 ft (SD). At completion of the program, their ambulation distance increased to 574 +/- 367 ft (increase in ambulation 298 +/- 290 ft, P less than 0.0001). Diagnostic subgroups improved to essentially the same extent. The increase in ambulation was not statistically different between non-COPD patients and a series of 317 patients with COPD. Patients severely impaired with chronic pulmonary disease other than COPD benefit from intensive pulmonary rehabilitation, and the degree of improvement is similar to that of COPD patients.