Objectives To update the knowledge on employment and the role of mastery, a personal factor reflecting the level of control over life and disease, among Dutch patients with ankylosing spondylitis (AS) compared to general population subjects. Methods Data of persons Results 214 patients and 470 controls (127 (59.3%) and 323 (68.7%) males; mean age 48.3 (SD 10.4) and 39.3 (SD 12.7) years, respectively) completed an online questionnaire. SER (95%CI) in patients was 0.83 (0.69-0.98); 0.84 (0.67-1.04) in males; 0.83 (0.59-1.07) in females. Adjusted absolute employment of patients compared to controls was 69% versus 84%; 73% versus 86% for males; 62% versus 78% for females. In multivariable analyses stratified for patients and controls, mastery was associated with being employed in patients, but only in those with low education. In controls, not mastery but higher education was associated with being employed. Conclusion Our study reveals that patients suffering from AS compared to population controls are less likely to be employed. Mastery is an important personal factor associated with employment in patients but not in controls. Interventions aimed at improving employment of patients with AS should likely account for mastery.