The Trust which runs Dewsbury and District Hospital received the third highest number of written complaints in the country.
Figures released by the Health and Social Care Information Centre show 1,411 complaints were made to the Mid Yorkshire Hospitals Trust in 2012/13.
It was the only NHS Trust in West Yorkshire to see the number of complaints increase year-on-year, and the local trust with the highest proportion of complaints upheld – 69.2 per cent.
But Mid Yorkshire’s chief nurse Sally Napper said: “We are continually striving to improve our care and patient feedback is very important.
“The Trust has a robust and accessible complaints procedure to ensure concerns are fully addressed.
“We know that we have more to do, but we are building on the progress made over the last year and will always take every opportunity to improve the quality of care.”