In recent years, academic journals have evolved to become a vehicle for scientific communication that is acknowledged by the official organizations that certify their quality. This enables assessments to be performed, determining how a discipline has evolved through the analysis of bibliometric indicators and the keywords used to index the articles. In the field of library and information science, it is particularly interesting to study the articles published in the journals specializing in this area but few studies have performed an in-depth analysis of the discipline. In order to gain a detailed view of the evolution of library and information science, we have carried out a bibliometric and thematic study of the journals Anales de Documentación (AD) and BiD textos universitaris en biblioteconomia i documentació (BiD) between 2000 and 2013. The analysis focuses on the number of articles and authors, the evolution of the sections and the contents. In addition, a thematic study determines the level of similarity between the two journals' contents, the subject areas they belong to and whether there is any subject continuity during the period analysed. The results confirm that in BID, practitioner-focused subject matter is double that of the academic content, unlike AD, which shows a preference for academic content. The thematic study confirms that there is little similarity between the content of the two publications; that the subjects where there is overlap are basically concerned with information units, information technologies, auxiliary sciences and techniques, and library science; and that there is little continuity in the subjects covered during the period analysed