A spokesman for Argentina's President Cristina Fernandez says she has undergone successful surgery to remove blood from inside her skull and relieve pressure on her brain.
The spokesman's statement says President Fernandez is in "her room, surrounded by her family and in good spirits".
Experts say the procedure to drill into her brain and relieve a subdural hematoma is generally low risk and almost always has positive results.
The president's condition appears to be the result of hitting her head during a fall in August, although she was cleared by her doctors at the time.
The operation will keep President Fernandez out of campaigning for the October 27th mid-term congressional elections.
Recent polls indicate the government could lose control of Congress in the mid-term vote, an outcome that would deprive Ms. Fernandez of the chance of introducing a constitutional reform that would allow her to run for a third term in 2015.
President Fernandez, who has been in office since 2007, had her thyroid glands removed last year after she was diagnosed with cancer, although later tests indicated no cancer was present.
Her husband, former president Nestor Kirchner, died after a heart attack in 2010.