Aim To determine whether focussed radiology training in reporting stroke computed tomography angiography (CTA) improved diagnostic performance of general radiology specialty trainees staffing regional on call rotas. Materials and methods A validated case archive (VCA) consisting of 50 hyperacute stroke CTA cases was developed for a full day course on CTA interpretation. Training days were organised ensuring all local trainees had a chance to attend. The rate of major and minor amendments by neuroradiology consultants were reviewed in 252 on-call radiology trainee reports. Results Before training, radiology trainees had a total discrepancy (reporting error) rate of 37%: 12% major, 25% minor. Following CTA training, the total discrepancy rate was not significantly reduced (34%) but there was a substantial reduction in major discrepancies to 4% (p=0.037; odds ratio = 3.30, 95% confidence interval [CI]: 1.08 to 10.12). Conclusion An intensive training course based on a hyperacute stroke VCA significantly reduced major discrepancies in stroke CTA interpretation for radiology trainees. The ability of radiology trainees to recognise large vessel occlusions and other significant findings improved.