Often the unwanted pets are dumped in the cold outside animal centres, which means some die.
Many other pet shelters are overrun with bunnies and they are worried Easter will make the situation worse.
An SSPCA spokeswoman said people buy baby rabbits at Easter when they are six or seven weeks old.
But when people go on holiday in June, they forget they have to find someone to look after them.
Other people just get bored of them.
The charity said if people were really serious about getting a bunny, they should offer a home to the many living in pet shelters.