Fife Animal Park, near Cupar, which is home to 76 species of animals including water buffalo, a zebra, meerkats and capybaras, closed yesterday.
The zoo, which is facing a probe by the charities watchdog, says it would re-house the animals.
But animal welfare charity OneKind's policy director Libby Anderson said: "OneKind has serious concerns about the situation of the animals at the Fife Animal Park.
"Previous experience shows that it is difficult to find suitable homes for exotic animals and it is essential that this is done with the participation of an animal welfare organisation such as the Scottish SPCA.
"Re-homing them is completely different to re-homing a domestic animal as their needs are extremely specialised."
She added: "While we hope that these animals will find happy endings, perhaps the fact that the park is closing is a sign that public opinion is turning against zoos and parks, and people no longer want to see animals kept in unnatural conditions purely for human entertainment."
The 10-acre park is home to animals including Agie the Highland cow and Houdini the goat.
Other animals which need to be to be rehomed include capybaras, water buffalo, a zebra and meerkats.
The park itself is owned by Peter and Jocky Lockhart while the animals and some of the equipment are owned by the Fife Animal Trust.
In October, the zoo was put up for sale for £500,000.
Scottish SPCA senior inspector Steven Gray said:"We will provide support to the council as required with regards the onward care of any animals which may require rehoming as a result of the closure of the facility."
The Fife Animal Trust said the reasons for the closure would be given later and said the animals would go to other zoos and parks.