A new league table based on healthcare services from 33 European countries has placed the UK 14th on the list.
The annual survey, which calculates a score based on a number of factors from medical results and patient information, showed the NHS had been dragged down by waiting lists and "uneven quality performance".
The Netherlands topped the list, with a score of 875 out of a possible 1,000 points. Denmark was second (819) and Iceland (811) was placed third.
The UK was awarded 682 points, putting it just one place behind Ireland (701). Bulgaria propped up the table with just 448 points.
The study was carried out by Brussels-based Health Consumer Powerhouse, and reported that the UK had a "mixed performance".
When the rankings are adjusted in line with per capita spending on health care, the UK comes 23rd in the table.
A Department of Health spokesman said the report is "based on flawed methodology and old data". He added that record investment in the NHS had given patients the "shortest waiting lists since records began".