At least 35,000 protesters packed central Madrid during the weekend, carrying banners while marching from Plaza Cibeles to the Puerta del Sol to protest against education cutbacks, El Pais reported Monday.
In Barcelona, 25,000 people turned out, while several hundred were seen in Valencia and Malaga.
Nearly every provincial capital held a similar demonstration where protesters held banners that read "More education, less privatization" and "Fewer political consultants and more teachers."
Spain's education system has one of Europe's highest dropout rates, with close to 30 percent of students leaving before they turn 16 years old.
Thousands of demonstrators also gathered outside the offices of the Spanish stock market in Madrid, protesting over capitalism and corruption.