"I'm marching against all the things that are going on - the lies, the inflation, [the treatment] of those in retirement. Let's put an end to the lies and the corruption," said a 73-year-old protester.
The woman, who gave only her first name, Edith, said she is still working because she can't afford to retire.
Demonstrations were held on plazas across Argentina, including in major cities like Cordoba, Mendoza and La Plata.
Protesters also turned up outside Argentine embassies and consulates around the world.
In Rome, about 50 protesters, all Argentine expats, held a noisy protest outside the consulate on Via Veneto. Among the slogans being shouted was "Cristina, go away."
The protests hold deep symbolism for Argentines, who recall all too well the country's economic debacle of a decade ago.
The "throw them all out" chants of that era's pot-banging marches forced presidents from office and left Argentina practically ungovernable until Fernandez's late husband, Nestor Kirchner, assumed the presidency in 2003.
The current president's supporters sought to ignore two earlier protests this year, but when it became clear the latest effort could turn out huge numbers, her loyalists came out in full force.
They dismissed the protesters as part of a wealthy elite, or beholden to discredited opposition parties, and misled by news coverage from media companies representing the country's most powerful economic interests.