The A&E departments at Dewsbury, Pontefract and Wakefield hospitals have topped national performance tables.
NHS England figures show 99.2 per cent of patients were seen, assessed and either discharged or admitted within four hours during the week beginning March 9.
It puts the Mid Yorkshire Hospitals Trust first out of 144 NHS trusts with A&E units for that week.
In the same week its A&E units were also the fifth busiest in the country.
The Trust had been ranked 86th at the start of the year.
Lead emergency medicine consultant Dr Sarah Robertshaw said: “Everyone has been working hard from the emergency department and ward teams, portering and housekeeping staff to the X-ray, laboratory and pharmacy team to the chief executive.
“This has been a genuine team effort to focus minds and get us through winter. Waiting time is wasted time and by planning better we have managed to create a leaner service.”
The Trust has changed its systems to make sure A&E patients are assessed as quickly as possible when they arrive.
Patients with minor injuries are treated rather than waiting for triage.
GPs also have direct access to speciality consultants before admission, meaning patients are moved through the system more quickly.
Other measures put in place during winter have included increased flu jabs and mobile pharmacists.
The Trust said its new ambulatory emergency units at Dewsbury and Pinderfields Hospital in Wakefield have also sped-up diagnosis and management of patients who are not critically ill.
Clinical commissioning groups have also been working alongside the Trust to encourage increased opening hours for GP surgeries, walk-in centres and pharmacies which can treat non-emergency patients.
Dr Robertshaw said: “The drop in waiting times has proved that the philosophy we have adopted in A&E and at the rest of the Mid Yorkshire Hospitals Trust has worked and must continue.”