Borth Animalarium said 32 dragons, which were cold and not moving, were left in a cardboard box on the counter by a friend of a disabled man who could no longer take care of them.
Staff warmed them and fed them, and found homes for eight of the animals.
They are a docile and quiet species, and require a heated tank, light and UV sources.
Animalarium owner Jane Mumbray said: "Many people bred bearded dragons last year as they were selling for Â£80 each in some pet shops. However, there are so many of them about now they do not sell.
"They are probably the best pet lizard species of all. Bearded dragons greet each other by waving a front leg and will often greet their owner in the same way.
"It is not a light commitment to take on a pet lizard and should be taken seriously but they are a very rewarding pet."
A zoo in Ceredigion is looking for homes for 24 abandoned Australian bearded dragons.