"I know it sounds cruel but if he's going to do something he should divorce her and start all over again," he said, "[and] make sure she has custodial care and somebody looking after her."
Robertson, who is no stranger to controversial statements, was responding to a viewer whose friend began seeing another woman while still married to his wife, an Alzheimer's victim.
"My friend has gotten bitter at God for allowing his wife to be in that condition, and now he's started seeing another woman. He says that he should be allowed to see other people because his wife as he knows her is gone," the viewer, Andreas, wrote to CBN.
Robertson sided with the friend who decided to see another woman. But he indicated that the man should divorce his wife before seeing someone else.
"I hate Alzheimer's. It is one of the most awful things because here's the loved one, this is the woman or man that you have loved for 20, 30, 40 years and suddenly that person is gone. They're gone. They are gone!" the CBN founder said.
Co-host Terry Meeuwsen challenged Robertson's response, noting that when couples marry they vow "for better, for worse."
But Robertson stated, "You said 'till death do us part;' this (suffering from Alzheimer's) is a kind of death."
"I certainly wouldn't put a guilt trip on you if you decided that you had to have companionship; you're lonely."
According to the Alzheimer's Association, Alzheimer's is a type of dementia that causes problems with memory, thinking and behavior. Symptoms usually get worse over time.
It is the sixth leading cause of death in the United States and is the only cause of death among the top 10 in America without a way to prevent, cure, or even slow its progression.
Today, some 5.4 million Americans, most of them aged 65 and older, are living with the disease. By 2050, as many as 16 million will have the disease.
Most people survive an average of four to eight years after an Alzheimer's diagnosis.
"I know a man who went to see his wife every single day and she didn't recognize him one single day," Robertson said on the show. "And she would complain he never came to see her.
"It is hurtful because they say crazy things. She finally died. ... It is a terribly difficult thing for somebody."
With that said, the broadcaster went back to the viewer's dilemma and said, "I can't fault them for wanting some kind of companionship. If he says in a sense she is gone, he is right. It is like a walking death."
"The last thing I would do is condemn you for taking that kind of action."
Acknowledging the weight of the ethical question, he advised that the viewer receive guidance elsewhere.
"Get some ethicist besides me."