Roisin Shortall says the health service is dysfunctional "in lots of ways".
The Dublin North West TD and former Minister of State for Primary Care has been addressing delegates from the Irish Medical Organisation at their conference in Croke Park today.
Patient waiting lists and hospital overcrowding are among the topics being discussed.
Deputy Shortall says it is difficult to even trust the data we have on the health service;
"We've very little data about the health service," she said.
"It's dysfunctional in lots of ways and what we need to do is reform it.
"The Taoiseach was talking about 'can we believe the waiting lists?' - there is a problem there with data in the health service, but we also know that the reality is that very large numbers of people... are waiting for services."