In chronic obstructive pulmonary disease (COPD), accessory respiratory muscles are recruited as a compensatory adaptation to changes in respiratory mechanics. This results in shortening and overactivation of these and other muscles. Manual therapy is increasingly being investigated as a way to alleviate these changes. The aim of this study was to measure the immediate effect on lung function of a soft tissue manual therapy protocol (STMTP) designed to address changes in the accessory respiratory muscles and their associated structures in patients with severe COPD. Twelve medically stable patients (n=12) with an existing diagnosis of severe COPD (ten: GOLD Stage III and two: GOLD Stage IV) were included. Residual volume, inspiratory capacity and oxygen saturation (SpO ) were recorded immediately before and after administration of the STMTP. A Student's -test was used to determine the effect of the manual therapy intervention ( <0.05). The mean age of the patients was 62.4 years (range 46-77). Nine were male. Residual volume decreased from 4.5 to 3.9 L ( =0.002), inspiratory capacity increased from 2.0 to 2.1 L ( =0.039) and SpO increased from 93% to 96% ( =0.001). A single application of an STMTP appears to have the potential to produce immediate clinically meaningful improvements in lung function in patients with severe and very severe COPD.