Although total hip replacement (THR) has been proven to be effective, the effect of THR on employment in ankylosing spondylitis (AS) in Chinese population is still unknown. We aimed to demonstrate whether or not patients with AS returned to work following THR and factors associated with the work ability after THR. We performed a retrospective study including a total number of 128 AS patients undergoing THR between 2009 and 2013. Presurgery and postsurgery data including disease state, work status, type of job, and time of resuming work were collected. Factors associated with early return to work were assessed through ordinal regression. Eighty-seven of 128 patients (68 %) were employed within 1 year before THR and 98 returned to work after surgery. Among them, 21, 46, and 31 resumed work by 3, 6, and 12 months postoperation, respectively. Multivariate ordinal regression showed that patients with unilateral THR, younger age, lower BASFI score, employed presurgery, and low or moderate physical demand were more likely to resume work earlier. Most individuals working presurgery returned to work after THR. For young AS patients with hip involvement, THR is an effective treatment for improving and maintaining work ability.