Hundreds of deaths in Wales annually could have been avoided established guidelines were followed to prevent blood clots, according to the Assembly's Health and Social Care Committee.
The Welsh Government says it welcomes the report and will consider its recommendations carefully.
"This is a substantial problem in relation to its scale" says the committee's chair Mark Drakeford AM.
"But it's a manageable problem. It's a problem that things can be done about, practical things, things that can be done today and are within the ability of the NHS to do".