Richard Gunn, 52, was driving the lawn mower down a street in the northern New Zealand town of Dargaville late Monday evening when police stopped him, police spokeswoman Sarah Kennett said.
Gunn's breath alcohol level was at more than twice the legal limit for drivers, police said, and he previously had lost his driver's license.
Gunn said he has been using the lawn mower to get around town since losing his license.
"I thought I was safe," he told TV One News.
Even bicycles went faster than the lawn mower's 5 mph, he said. "I've watched them go past me."
Gunn was scheduled to appear in court later this week on charges of careless driving, driving while disqualified and driving with excess breath alcohol. He faces a potential prison term if convicted.
Police impounded the lawn mower for 28 days.
