OBJECTIVES: To create an evidence map of the different patient-reported outcome instruments used in studies of patients with ankylosing spondylitis, the geographical settings in which these studies were conducted and the interventions assessed. METHODS: We searched the heoro.com database (www.heoro.com) for PRO studies on ankylosing spondylitis published between 1960 and December 7 2016, and analysed the abstracts identified by the search to determine the different PRO instruments cited across the range of geographical locations and interventions. We presented the findings as an evidence map. RESULTS: We found a total of 128 abstracts that reported the use of 64 different PRO instruments. Of these, 22 instruments were specific for ankylosing spondylitis or other inflammatory arthritis, 27 were general instruments used to evaluate quality of life or utilities, 12 assessed non-disease-specific symptoms, in particular fatigue, or other conditions or diseases that were common comorbidities of people with ankylosing spondylitis, and three evaluated the impact of the disease on work productivity. The most frequently used tool was the BASDAI, cited in 66 abstracts, followed by the BASFI (54 abstracts), SF-36 (52 abstracts), AS Quality of life questionnaire (34), Health Assessment Questionnaire (20) and the EQ-5D (14). The Netherlands was the most frequent location for the studies, with 16 abstracts, followed by the United States (14 abstracts), then Germany, Turkey and the United Kingdom (12 abstracts each), then Canada (11 abstracts). Interventions assessed were generally targeted therapies such as TNF inhibitors and physical therapies. CONCLUSIONS: A wide range of PRO tools have been used in studies of ankylosing spondylitis from a wide range of locations, but only nine tools and six countries were cited in more than 10 abstracts.