Background and aim: Recognition of structured training in endovascular aortic repair (EVAR) for vascular trainees is increasing. Nevertheless, how trainees can achieve sufficient skills in EVAR sizing and graft selection is sparsely described. The aim of this study was to investigate the effect of systematic training in basic EVAR sizing and graft selection on vascular surgery trainees using a validated assessment tool. Methods: Sixteen vascular surgery trainees were included in an intensive 6-h hands-on workshop in aortic sizing and stent graft selection for EVAR with a trainer-to-trainee ratio of 1:2. After 1-h lecture, participants did 5 h of supervised training on increasingly complex cases. Finally, the participants were tested using a validated assessment tool. Results: All participants were able to size the test-case and select a stent graft combination in 24:35 (13:30–48:20) min (median and range). The participants’ overall test scores (lower is better) were in median 17.9 (11.9–28.4). This did not differ from the scores of experienced EVAR operators 14.7 (11.7–25.2) (<200 EVAR’s) (p =.32) but was inferior to the score of EVAR experts 11.2 (9.8 –18.7) (≥200 EVAR’s) (p =.01). The sub-score for anatomical measurements was 10.6 (3.9–18.8) and comparable with the experienced group 9.7 (8.1–12.8) (p =.83) but inferior to the expert operators 6.5 (5.2–10.2) (p =.04). The sub-score for stent graft selection was 7.5 (4.9–14.1) and comparable with experienced operators scoring 4.5 (3.6–12.3) (p =.09) but inferior to the expert operators score of 5.0 (3.6–8.4) (p =.01). Conclusion: This study presents the results of a standardised one-day basic EVAR sizing and graft selection workshop. Vascular surgery trainees with no prior EVAR experience learned to size and select stent grafts for a simple infra-renal AAA on par with experienced EVAR operators.