Background: A consensus about the best weaning procedure, haven't been reached. Patient–ventilator dyssynchrony can lead to considerable patient distress, prolongs mechanical ventilation and (ICU) length of stay. PAV+ delivers positive pressure ventilation in proportion to instantaneous inspiratory effort, reduces ventilator dyssynchrony and the duration of weaning from the ventilator. Aim: Evaluate weaning outcome for COPD patients using PAV+ versus PSV, assess patient ventilator asynchrony during weaning, compare ICU outcome (hospital length of stay, ICU and hospital mortality). Patients & Methods: 150 mechanically ventilated COPD patients were enrolled in this prospective, parallel randomized clinical trial and assigned to either PAV+ or PSV spontaneous breathing trial for weaning (after meeting specific eligibility criteria). Asynchrony was detected with bedside waveform interpretation of flow and airway pressure for 30 minutes. Results: Weaning success was recorded in 73.3% PAV+ vs. 66.7% PSV (P= 0.373). Asynchrony events was significantly less in PAV+ vs. PSV; ineffective triggering (14.9 ± 10.3 vs. 37.6 ± 26.6, p = 0.001), double triggering (3.01 ± 3.2 vs. 8.0 ± 5.8, p = 0.001) and delayed cycling (11.81 ± 6.95 vs. 15.20 ± 8.97, p = 0.006). Asynchrony index was significantly lower for PAV+ (7.05 ± 3.08 vs. 9.38 ± 4.07, p = 0.001) as well as duration of hospital stay (10.7 ± 4.0 vs. 13.1 ± 7.1, p = 0.047). Conclusion: PAV+ proved to be as successful as PSV in weaning of COPD patients. Significant reduction in patient ventilator dyssynchrony and hospital stay was noted with PAV+.