This study aimed to evaluate the effects of impairment on objective performance measures in Para athletes as a step towards developing an evidence-based classification system. Two groups of athletes comprising twenty-one elite Para athletes (classified Grades I to V) and eleven non-disabled athletes (competing at Prix St. Georges or Grand Prix) were measured whilst performing a 2-minute custom dressage test on a riding simulator and clinically assessed using a battery of impairment assessment tools. The dataset contains the measurements from both impairment assessments and performance tests.