The 68-year-old who captained Super Eagles to their first Africa Cup of Nations title in 1980 needed $50,000 for his medical care overseas.
Nigeria Football Federation sought financial support for Chukwu and billionaire Femi Otedola came to his rescue by providing the money for his trip abroad.
Chukwu has thanked NFF president Amaju Pinnick and other Nigerians who came to his aid.
“I am very happy with the efforts of the Nigeria Football Federation through the President, Amaju Melvin Pinnick,” Chukwu was quoted by the Nff website.
“He has proved that he is truly the father of Nigerian Football. I am also grateful for the support and prayers of other Nigerians.”
On the nature of the illness, he said: “It is waist pain and stomach upset that I keep feeling.
“The doctors in Nigeria have treated the stomach upset and it remains the waist pain, but I am confident that I will come back to Nigeria having regained sound health.”
Chukwu was the assistant coach to Clemens Westerhof when the Super Eagles won a second African Cup of Nations title in 1994.
He also coached the side between 2002 and 2005, leading the West Africans to win a bronze medal at the 2004 Africa Cup of Nations in Tunisia.