"The elephant lifted him up with his trunk and smashed him onto a water tank next to the cage," said Nguyen Van Sang, an official at the Dai Nam tourism centre where the zoo is located in southern Binh Duong province.
He said the victim was well known by the elephant, which had been at the zoo since the age of two in 2008.
The handler, Doan Huu Tai, 27, was rushed to hospital after the attack on yesterday but did not survive, Sang told AFP.