The former ruler, notorious for his reign of terror, had slipped into a coma and doctors said earlier he had little chances of surviving.
“He’s out of a coma and his condition is improving,” sources at the King Faisal Specialist Hospital told the French news-agency AFP.
“However, he remains in the intensive care unit,” they added.
Now in his eighties and in exile in Saudi Arabia, Idi Amin had been admitted to the hospital on Friday.
Doctors earlier said Amin was in a vegetative state and could die anytime.
He had ruled Uganda from 1971 to 1979 and his reign is best remembered for the attendant brutality.
Up to 400,000 people were estimated to have been killed during the period.
“If Amin comes back alive, he would be prosecuted for the atrocities that he committed against the people of Uganda.” -- Ugandan President Yoweri Museveni
On being ousted by Tanzanian forces and Ugandan exiles, the portly Amin slipped out of the country and first surfaced in Libya. He then secured asylum in Saudi Arabia, where he has been living for the past 10 years.
Despite persistent calls by international human rights organizations for his prosecution for genocide, Amin has never had to stand trial.
He has not set his feet again in Uganda, since he was driven out.
Ugandan President Yoweri Museveni, meanwhile, has warned that Amin would face trial for his atrocities if he returned to his homeland alive.
“If Amin comes back alive, he would be prosecuted for the atrocities that he committed against the people of Uganda,” a statement from Museveni said.