Background While decreased hip abductor strength, functional performance, and self-reported instability scores have all been shown in association with CAI, any sex difference in the relationship between these indicators is unclear. This study was to determine whether sex differences are present in the relationship between these indicators in individuals with CAI. Methods Thirty-two women and twenty-nine men with unilateral CAI took part. Hip abductor strength and functional performance were respectively assessed using a hand-held dynamometer and the figure-8-hop test. All 61 participants scored the Cumberland Ankle Instability Tool (CAIT) for self-reported ankle instability. Independent sample t-tests and correlation analysis were conducted. Results Normalized hip abductor strength and functional performance measures for females were lower than for males. The self-reported ankle instability CAIT score, where higher values represent less instability, was significantly and positively correlated with both normalized hip abductor strength (p = 0.003) and functional performance (p = 0.001) on the affected side in females, but not in males (p = 0.361 and p = 0.192 respectively). Conclusions Sex differences were observed in that there were significant relationships between normalized hip abductor strength, functional performance, and CAIT scores in female CAI participants, but not males, suggesting that CAI evaluation and rehabilitation strategies should be sex-specific.