Introduction: Maximum inspiratory pressure (MIP) and the rapid and shallow breathing index are predictors for successful extubation. Peripheral muscle strength and functionality appear as possible predictors of success for extubation in other patient profiles, however, there is little evidence in patients undergoing to Coronary Artery Bypass Grafting (CABG). Objective: To assess peripheral muscle strength and functionality as predictors of success for extubation in patients undergoing to CABG. Methods: Prospective cohort study. At the time of hospital admission, patients were assessed for MIP, maximum expiratory pressure (MEP), Medical Research Council (MRC), peak of expiratory flow (PEF) and Functional Independence Measure (FIM). Patients were divided into two groups: Success Group (SG), which remained on spontaneous ventilation for more than 48 hours, and failure group (FG) that required invasive support in less than 48 hours. We compared the influence of muscle strength, cough and functionality variables between these groups. Results: 74 patients, Success Group (n = 59) and Failure Group (n = 15), were evaluated. The CI 95% was -1 (-5.33 to 3.33) in MIP, 4 (2.14 to 5.86) in MEP, 13 (-35.31 to 61.31) in PEF, 7 (6.27 to 7.73) in the MRC and 9 (8.08 to 9.92) in the FIM. Conclusion: Peripheral, expiratory muscle strength and functionality demonstrated a statistically significant influence on the success of extubation in patients after CABG.