In March 1969 he was hit by a car while walking on a sidewalk in Toronto. He was seriously injured, suffering a broken hip and kidney injuries. A benefit concert was held on May 4, 1969, with two dozen acts that included Ian and Sylvia Tyson, John Lee Hooker, and Hagood Hardy. He never fully recovered from his injuries and suffered what was described as a stroke. He was able to return to the stage for one performance at Massey Hall on February 23, 1970, walking with the aid of a cane, to sing a couple songs with Buddy Guy; Johnson received a standing ovation.