Commercial advertising is the main tool for marketing goodsand services offered by businessmen in the market due to theeasy access to final customers and its capacity to influence theirpurchase decisions. Norms on advertising are directly related tothose on unfair competition. For this reason, the European Union,aware of its importance for the development of internal market,has created a number of norms to regulate commercial advertisingand to eradicate all ads that may imply unfair actions that canirregularly alter the market and indiscriminately affect competitorsand consumers. Spain was required to transpose communityregulatory provisions to its national law; compliance with thisrequirement involved significant and complex modifications of theexisting advertising system.