The fall was partly achieved through extra operating sessions
The number of people in Northern Ireland waiting more than 18 months for surgery has been cut by more than a fifth.
The 20% reduction by the Royal Group of Hospitals was recorded over an eight month period up to March.
It means the hospitals have met a target they publicly announced last summer.
The fall was partly achieved through extra operating sessions.
The figures come three weeks after an independent report suggested that nearly 40% of weekday operating theatre capacity was not being used in hospitals across Northern Ireland.
The Audit Office report examined the use of operating theatres in the province.
The report, produced by Comptroller and Auditor General John Dowdall, found that using operating theatres "to their optimum" could directly contribute to the reduction in waiting lists and the length of time which patients have to wait for treatment.