Most pulmonary rehabilitation (PR) programs do not currently incorporate IMT in their PR programs for COPD patients. The aim of the present study was to assess the influence of adding IMT to the patients already involved in a rehabilitation program. Thirty-four patients with significant COPD were recruited for the study. All patients participated in a general exercise reconditioning (GER) program for 12 weeks. The patients were then randomized to receive IMT or sham IMT, in addition to GER for the next 6 months. Following three months of GER training there was a significant increase in the 6-min walk test (6MWT) (from mean+/-SEM 254+/-38 to 322+/-42 m, p<0.01), and small but non-significant decreases in the perception of dyspnea (POD), and in the St. George Respiratory Questionnaire score (SGRQ). Following the addition of IMT to the GER program there was a significant increase in the PI(max) in the GER+IMT group (from 66+/-4.7 to 78+/-4.5 cm H(2)O, p<0.01). This was accompanied by a significant improvement in the POD and a further significant improvement in the SGRQ score. IMT provides additional benefits to patients undergoing PR program and is worthwhile even in patients who have already undergone a GER program.