OBJECTIVES: The endovascular aneurysm repair (EVAR) trials aim to assess the efficacy of EVAR in the treatment of AAA in terms of mortality, quality of life, durability and cost-effectiveness. DESIGN: Male and female patients aged at least 60 years with an AAA diameter measuring at least 5.5 cm on a computed tomography (CT) scan are assessed for anatomical suitability for EVAR. Suitable patients are offered entry either into EVAR Trial 1 if they are considered fit for conventional open repair or EVAR Trial 2 if they are considered unfit. EVAR 1 randomly allocates patients to EVAR or open repair and EVAR 2 randomly allocates patients to EVAR with best medical treatment or best medical treatment alone. Target recruitment for EVAR Trials 1 and 2 is 900 and 280 patients, respectively. PROGRESS: Recruitment began in September 1999 and there are currently 40 UK centres participating in the trials. Monthly targets are being exceeded in EVAR Trial 1 with 1037 patients randomised by October 2003. EVAR Trial 2 is also meeting monthly targets with a total of 319 patients randomised. When recruitment closes in December 2003 patients will need to be followed for at least 1 year from their operation. Publication of full results for both trials is expected in mid 2005.