Hi Concerned,
There is an official college of qualified real estate agents in Spain
http://www.coapi.es/es
However, membership of this is not a legal requirement. Anyone can set themselves up as an estate agent in Spain, without any training or qualifications.
It also depends on the region. In Catalonia, for example, estate agents have to register with the Generalitat (regional government) and comply with certain requirements in order to operate and get a registry certificate, which has to be displayed in the company office.
In many parts of Spain, especially on the costas, there is no control or regulation. It’s like the wild west. But anyway, what good does regulation do? In the boom years, some of the biggest estate agents on the Costa del Sol were properly registered and licenced, whilst also being run by crooks.
Where are you looking?