In a nationally televised address, an energetic Ms Fernandez announced the creation of a programme to encourage young, unemployed Argentines to study with a £50 subsidy.
She also criticised those who speculated about her condition during her absence.
The president said: "It's true I've had some difficulties, but I'd like to see how others would fare if they had to deal with the things that I've gone through. I'd like to see them running this country."
The 60-year-old president underwent surgery to remove a blood clot on October 8 and returned to work on November 18 but the normally talkative leader with a love of Twitter last spoke publicly on December 10 and last tweeted on December 13.
The uncharacteristic silence fed speculation in Argentina about her health.