Control of the Welsh NHS could be "grabbed back" by Westminster after the general election, Leanne Wood has claimed.
Health has been devolved in Wales since 1999 and is the responsibility of the Welsh Labour Government.
But the Plaid Cymru leader fears the Tories could "grab back" powers if they increase their mandate on 8 June.
The Welsh Conservatives said it was a "cynical attempt to exploit uncertainty".
Speaking on the BBC's Sunday Politics programme, Ms Wood claimed if the Tories increased their majority at the general election they could try to take back powers from the assembly.
She pointed to the list of reserved powers in the recently passed Wales Bill, claiming it suggested there were some powers which could be "dragged back" to Westminster.
"The Tories have attacked the Welsh NHS quite viciously," Ms Wood said.
"If they increase their mandate then I wouldn't put it past them to try to take powers back from Wales over the NHS, and then, of course, we risk our NHS being privatised."
A spokesman for the Welsh Conservatives said: "Responsibility for the Welsh NHS has been a matter for the Welsh Government for a generation, so these claims are a cynical attempt by Plaid to exploit uncertainty over the devolved settlement and should be treated with the contempt they deserve.
"In fact, the Welsh Conservatives in government have strengthened the devolved settlement in recent years, and the recent Wales Bill offers greater clarity and accountability than ever before in the devolved era."