New figures show that the trust that runs York Hospital has one of the worst records for A&E waiting times.
NHS England has for the first time published data on the number of people attending A&E departments who have to wait more than 12 hours before being admitted, transferred or discharged.
And York Teaching Hospital NHS Foundation Trust has the ninth highest percentage of people waiting 12 hours-plus – out of a list of 120 trusts.
The figures show that in February, there were 8,990 total attendances at the A&E departments of York and Scarborough hospitals.
The number waiting more than 12 hours was 1,690 – or 18.8%.
That was the worst performance of any Yorkshire trust.
Barking, Havering and Redbridge University Hospitals NHS Trust had the highest percentage of 12 hour-plus waits, at 31.3%.
A total of 24 trusts had fewer than 5% of A&E patients waiting that long.
A York NHS trust spokesperson said: “It is well documented our trust was under sustained pressure for several weeks resulting in the worst pressures on emergency services in our history.
“We recognise this meant many patients spent a long time in the emergency department before they were admitted to a ward, and we are sorry for this.
“Our staff worked exceptionally hard in the most difficult of circumstances.”