Brandishing a copy of the leaflet, Clinton said: "Senator Obama knows it is not true that my plan forces people to buy insurance even if they can't afford it."
"It is blatantly false and yet he continues to spend millions of dollars perpetuating falsehoods ... It is destructive, particularly for a Democrat to be discrediting universal healthcare."
"Let's have a real campaign. Enough with the speeches and big rallies and then using tactics that are right out of Karl Rove's playbook," she said, referring to the Republican political strategist credited for George Bush's winning presidential campaigns.
Obama, an Illinois senator who has won 10 consecutive states nominating contests, said the contents of the leaflet were accurate.
He said he was puzzled by his rival's "change in tone".
"The notion that somehow we're engaging in nefarious tactics I think is pretty hard to swallow," he told reporters. "There's nothing in there that's factually inaccurate."
The party's nomination contest has become increasingly bitter since Obama recently overtook Clinton in the race for delegates for the summer's Democratic convention.
Some analysts have said Clinton must win contests in the states of Ohio and Texas on March 4 if she is to cut Obama's lead and still have a chance of winning the nomination.
Targetting Obama's campaign focussing on "change", she said George Bush, the US president, who campaigned on a platform of "compassionate conservatism," had also used the same theme.
"He promised change, didn't he?" she said. "The American people got shafted and we're going to have to make up for it."
Obama meanwhile, criticised Clinton at a rally on Saturday in Ohio for switching positions on the North American Free Trade Agreement (Nafta), which he said she had lauded as a success of her husband's administration.
He said: "You can't be for something or take credit for an administration and 35 years of experience and then when you run for president suggest somehow that you didn't really mean what you said back then.
"It doesn't work that way."