We examine open access to the Spanish scientific literature through investigation of a sample of peer reviewed articles in seven subject categories. Of the 28,259 papers published in 2000, 26.89 % were freely accessible with the share varying among disciplines. Articles in the Social and Behavioral Sciences were the most available for free. This disciplinary divide applies also to the strategies used to offer open access to documents. In Clinical Medicine, Life Sciences, Arts and Humanities and Social Sciences open access was mainly based on the publishers side while subject based repositories were dominant in Physical, Chemical and Earth Sciences and deposit in home pages was the preferred strategy in Engineering, Computing and Technology. Institutional and general repositories seem to play a minor role in providing free access to the Spanish peer reviewed literature.
Random sample of 10 %: the number of documents published in the year 2000 analyzed was 2,856.
If the green and gold routes to OA are interpreted (as suggested in the introductory
paragraphs) as being active as opposed to passive diffusion mechanisms, thus it must be
concluded that overall, Spanish peer reviewed literature is driven to OA by a major passive
mechanism through the publisher website or editorial strategy.