Introduction: Gait speed can be applied, predicting outcomes associated with hospital stay such as length of stay and/or discharge. Despite these studies that correlate gait speed with the aforementioned outcomes, when we deal with cardiac surgery there is a gap. Objective: Verify whether gait speed is associated with the risk of hospital readmission in the postoperative period of coronary artery bypass grafting. Methodology: This is a prospective cohort study. In the preoperative period, all patients underwent a 10-meter gait speed test and repeated at hospital discharge. After the repetition of the gait speed test, patients were divided into two groups: slow and non-slow. Those who were not discharged walked less than 1.0 m/s occupied the slow group and those who were above 1.0 m/s were classified as not slow. Patients were followed for six months to observe the primary outcome, which was the need for hospital readmission. Results: The 6 months rate of readmission was 58%(14/24;95%CI49%to80%) among slow walkers and 17% (6/36;95%CI13%to46%) among non-slow walkers(p=0.002).In univariate analysis, gait speed, treated as a continuous variable, was associated with the primary outcome (HR0.6;95%CI0.2to0.9), while age, gender, BMI, MV and CPB time were not. In the multivariate model including age, gender, BMI, MV and CPB time, gait speed remained the only variable associated with readmission (multivariate HR:0.5,95%CI0.1to0.7p=0.02). Conclusion: Our data suggest that gait speed is associated with hospital readmission in patients undergoing to coronary artery bypass grafting.