Ankylosing spondylitis is a systemic rheumatic disease that affects the axial skeleton, causing inflammatory back pain, structural and functional changes which decrease quality of life. Several treatments for ankylosing spondylitis have been proposed and among them the use of exercise. The present study aims to synthesize information from the literature and identify the results of controlled clinical trials on exercise in patients with ankylosing spondylitis with the New York modified diagnostic criteria and to assess whether exercise is more effective than physical activity to reduce functional impairment. The sources of studies used were: LILACS, Pubmed, EBSCOhost, B-on, personal communication, manual research and lists of references. The criteria used for the studies selection was controlled clinical trials, participants with New York modified diagnostic criteria for ankylosing spondylitis, and with interventions through exercise. The variables studied were related to primary outcomes such as BASFI (Bath Ankylosing Spondylitis Functional Index) as a functional index, BASDAI (Bath Ankylosing Spondylitis Disease Activity Index) as an index of intensity of disease activity and BASMI (Bath Ankylosing Spondylitis Metrology Index) as a metrological index assessing patient's limitation on movement. From the 603 studies identified after screening only 37 articles were selected for eligibility, from which 18 studies were included. The methodological quality was assessed to select those with an high methodological expressiveness using the PEDro scale. A cumulative meta-analysis was subsequently performed to compare exercise versus usual level of physical activity. Exercise shows significant statistical outcomes for the BASFI, BASDAI and BASMI, higher than those found for usual level of physical activity.