Donald Marshall Jr., who has been at the centre of two of the country's most prominent legal battles, was reported in good condition following a double-lung transplant.
The native rights activist, once wrongfully convicted of murder, underwent the eight-hour operation on Monday in Toronto.
A friend in Halifax said Marshall's new lungs were functioning, but doctors were watching closely for signs the body would reject the organs.
On Tuesday, he regained consciousness and gave his wife a wink, said Terry Paul, chief of the Membertou reserve.
Suffering from chronic obstructive pulmonary disease, Marshall had been waiting for a transplant since December. He was operated on with only a few hours notice.
The Mi'kmaq from Nova Scotia made national headlines in 1983 when he had his conviction overturned. He had spent 11 years in prison for a murder he didn't commit.
In 1999, Marshall prevailed in a lengthy legal battle that resulted in a Supreme Court of Canada ruling that aboriginal people have the right to earn a living from fishing and hunting.
He had been arrested while fishing for eels out of season.