Wyn Crew said people who have a terminal illness should be allowed to seek help to die.
Mrs Crew, from Liverpool, travelled to Switzerland with her 74-year-old husband in January.
"
I know we did the right thing
"
Wyn Crew
Mr Crew had motor-neurone disease and faced creeping paralysis if he remained alive.
He killed himself with the help of the "assisted suicide group" Dignitas in Switzerland.
He died after taking a fatal dose of barbiturates prepared by a doctor.
Relaxed laws
The former docker was the first UK citizen to take advantage of the more relaxed Swiss laws.
Swiss law does not state that assisted suicide is legal but the practice is widely considered as a "humane act".
Mrs Crew told BBC Radio 4's Woman's Hour programme, she had no regrets about the trip to Switzerland.
"I couldn't have let him suffer," she said. "I know we did the right thing."
Mrs Crew urged ministers to consider changing the law.
"I'm not saying euthanasia across the board but voluntary euthanasia especially if someone is terminally ill and have no hope of recovery. Why should you have to suffer right through to the end?"
She added: "If they had a referendum I believe most people would support a change in the law."
Mrs Crew is being investigated by Merseyside Police. They have yet to take any decision on whether she will face criminal charges after helping her husband to travel to Switzerland to end his life.
But Mrs Crew insisted she had no regrets.
"If the police want to put me in jail for accompanying my husband then so be it."