"It is with profound sadness that I share with you that my continued battle with esophageal cancer is coming to an end. ... I look forward to spending my final days in comfort and peace with [wife] Nita by my side," the 76-year-old Hall of Fame player said in a statement released Friday through the Twins.
Killebrew's condition prevented him from throwing out the ceremonial first pitch last month at the team's home opener.
Former teammate Tony Oliva stepped in and made the pitch to Killebrew's grandson Casey, Sports Network reported.
At that time Killebrew was in Arizona undergoing continued treatment.
"I have exhausted all options with respect to controlling this awful disease," his Friday statement said. "My illness has progressed beyond my doctors' expectation of cure."
Killebrew said he has spent the "past decade of my life promoting hospice care and educating people on its benefits. I am very comfortable taking this next step and experiencing the compassionate care that hospice provides."