Established in 1952 by Miguel Sánchez-Mazas, THEORIA is one of the leading philosophy journals in the Spanish-speaking world and a well-ranked publication in the European Science Foundation index (ERIH: INT2). THEORIA cooperates with two Spanish philosophical societies: SOLOFICI and SEFA.

It is regularly indexed in the following databases: Arts & Humanities Citation Index®, ISI Alerting Services, SCOPUS, Current Contents®/Arts & Humanities, DOAJ, Bulletin Signaletique 519, ICYT, ISOC, MathSci,Mathematical Reviews, Current Mathematical Publications, Philosopher's Index, Repertoire bibliographique de la Philosophie. It also features prominently in national databases such as DICE and MIAR.

THEORIA is a non-profit editorial venture. It is published by the University of the Basque Country under a Creative Commons Licence. It is part of the Open Journal System (OJS) and all its papers (from 2003 onwards) are freely available on-line.