In recent years, there has been a growing interest in the development of quality rankings of universities, both nationally and internationally. The lack of clarity in the collection and presentation of information means that many of these classifications are difficult to understand and interpret, so that it is necessary to establish a series of considerations about the name of ranking, selection criteria, the weight indicators, the type and choice of institutions that are evaluated, the size of the institutions, information sources, the one-dimensionality/multi-dimensionality of the rankings, frequency and quality criteria. In addition to providing this information, the aim of this study is to update and improve the research ranking of Spanish public universities of 2009. The same methodology as in the ranking of 2008 is followed, adding a new criterion, which refers to the patents registered and operated, and also enhances the rate of research sections. Results allow the analysis of the strengths and weaknesses of each Spanish public university in the area of research.