The aim of this study was to investigate the effect of a cognitive task on standing postural control of the injured and non-injured leg of athletes with chronic ankle instability.MethodsPostural stability was measured by center of pressure parameters while chronic ankle instability patients (n = 8) randomly performed single and double leg standing in isolation or concurrently with a digit-backward cognitive task.ResultsAfter performing a concurrent cognitive task, anteroposterior sway significantly decreased in injured leg (P < 0.05) and area significantly decreased in both injured and non-injured legs (P < 0.05). There was no significant difference in all center of pressure parameters between injured and non-injured legs.ConclusionThe findings confirm the effect of a concurrent digit-backwards memory task on single leg standing balance in chronic ankle instability patients but the response to cognitive loading was not significantly different between the injured and non-injured legs.