The economic evaluation of a patient education program "ankylosing spondylitis"-based on a randomised controlled prospective multi-center study design-compares program costs and savings in direct and indirect follow-up costs. The collection of health services and cost data was conducted by questioning staff (education programme costs) and patients (follow-up costs). The present study results are: program costs per patient range between 117 euro (10 participants per course) and 186 euro (6 participants per course). Savings in indirect costs (unfitness to work) amount to 2500 euro and thus overcompensate program costs. Currently patient data are verified by sickness fund data and direct follow-up costs and qualitiy of life data are analysed.