Zohn, 35, was recently diagnosed with a rare form of Hodgkin's disease.
Zohn appeared on The Early Show Wednesday with a new 'do. His trademark brown locks were off his head, and in a clear plastic bag at his side.
Zohn told co-anchor Maggie Rodriguez he cut his hair off because he will be undergoing three months of chemotherapy treatments and then radiation.
"I figured I'd shave it off before it started falling out on its own," he said.
Zohn said he kept his hair as a "memory," but added that having his hair cut was liberating.
"I've had this mop of hair for so long, and cutting it, I was a little nervous," Zohn said. "But I think it's what it represented, 'All right, I have cancer, and I got to shave my head because it's going to fall out on its own.' That was the emotional part of it."
Rodriguez mentioned how appearances can be deceiving. She said many people would see Zohn, who is young and fit, wouldn't understand how he was diagnosed with cancer.
"I'm still trying to figure that out," Zohn said. "You always figure, 'Why me?' but I don't know. Cancer doesn't choose. No matter how much money or something I won on 'Survivor,' cancer doesn't care. It can get to you, but that's why I'm here. I want to let everyone know that it's OK, you can fight it; you can get through it."
And Zohn is mentally gearing up for this challenge.
"I'm ready to battle this and crush it out of my system," he told Rodriguez, "and hopefully educate and inspire others who are facing the same problems right now."
Zohn said he was diagnosed after dribbling a soccer ball 550 miles for his charity, Grassroots Soccer. He had itchy skin, night sweats, insomnia and lost weight. Zohn said doctors found a swollen lymph node, from which they identified as Hodgkin's disease.
The diagnosis was startling for Zohn, particularly after losing his father to cancer when he was 14 years old.
"It's scary, I'm not going to lie to you," Zohn said. " ...Your life flashes before your eyes ... but it's a good thing. I think I'm excited for this, and I'm ready to tackle it head-on."
Zohn said it's possible he was diagnosed with cancer because he has an opportunity to do something about it. He urged people with symptoms to see their doctor.
"If it can happen to someone like myself -- a young, fit, normal guy -- then it can happen to you."
The American Cancer Society estimates that there are 8,510 new cases of Hodgkin's disease each year and 1,290 deaths. Children and adults both get the disease.
Zohn now faces months of treatment, but said friends, family and his "Survivor" girlfriend, Jenna Morasca, from the sixth season of the show, are around to support him.
He said, "I think it's all gonna be OK. ...I'm ready."