The 1986 World Cup champion's personal doctor said Maradona had an accumulation of blood on his brain.
The neurologist said the problem was likely to have been caused by an accident, but Maradona does not remember such an event.
"He has a subdural hematoma," Leopoldo Luque told journalists.
"We will do it [the surgery] today."
Maradona was admitted to a private hospital with signs of depression on Monday, three days after his 60th birthday.