Introduction:In 2009, Dias and colls made a contribution to this field by applying the first functional 50-M Walk Test (50MWT) in the Coronary Intensive care Unit (CICU), being able to direct the exercise prescription as well as evaluate the response to a cardiovascular rehabilitation program during hospitalization. As the Cardiovascular Rehabilitation Program 1 (CVR1) does not yet recommend the 50 MWT in CVR1 due to safety measures and cardiovascular repercussion on the program, the inclusion of this tool is necessary as it concerns a population at risk. Objective: Compare the functional response and cardiovascular 50 MWT in patients with ACS who underwent CVR1.Methodology: Single-arm clinical trial, conducted with ACS patients admitted to the CICU of a private Hospital in Salvador -Brazil, from 24 to 48 hours post-event. The inclusion criteria consisted ACS patients with medical permission to walk, and had not been submitted to acute surgical treatments, aged ≥ 18 years who were oriented in time and space. Exclusion criteria included patients with orthopaedic problems, neurological sequelae and the inability to walk independently. Results:A total of 66 patients were gathered to compare the response to tests before CVR1 and at the time of discharge; data of systolic arterial pressure (SBP), heart rate (HR), perceived exertion rate by the Borg Scale (BS), time and speed of walking were evaluated. Measurements were obtained in the supine, seated and orthostatic positions, at the end of the walk, after 5 minutes rest, and walking duration. Statistical significance for SBP, in the time of walking and BS was observed (p ≤ 0.05). HR presented no statistical significance; predominance was shown in the absence of adverse effects in 89.4% of patients. Conclusion:This sample proved that patients who underwent CVR1 program presented an impact on functional capacity interpreted by an increase in walking speed, perceived exertion rate decreased and better blood pressure control during hospital discharge. Furthermore, 50 MWT might safely be applied as a tool before beginning CVR1, and as a method of assessing cardiovascular repercussion in the hospital phase after the program.