The man was attacked while using an outside shower at a fishing camp near Mana Pools National Park, Johnny Rodrigues, chairman of the Zimbabwean Conservation Task Force told German news agency DPA.
The area, located on the Zambesi River, is popular with hunters, most of whom stay in basic camps that offer little protection against attack by wild animals.
The attack is the latest in a string of lion attacks in the area, Mr Rodrigues said.
Eight villagers were killed in a spate of lion attacks over a period of about two months this year, he said. Those attacks only stopped when a pride of lions was killed.
The dead man, a tourist, was named as Pete Evershed by the iAfrica website.
The site said that he had been attacked by four or five lions and his wife, who witnessed the attack, could do nothing to save him.
Locals have claimed that lions in the area were being lured into camps with meat by tour operators.
Conservationists say the high level of wildlife poaching in Zimbabwe is robbing predators, such as lions, of food and making animals more aggressive.
Source: telegraph.co.uk