This paper investigates the changes of the productivity of the Spanish Public Universities during 1995-2006. The methodology to study productivity growth is the nonparametric Malmquist index. Its decomposition into technological change and efficiency change indicators allows to study the catching-up effect, the scale effect and the frontier-shift effect. Four different specifications are made to assess Spanish public universities: “general-model”, “teaching-only”, “research-only” and “knowledge transfer-only” model. In the four models, it can be observed an important conclusion: the importance that efficiency has as a source of growth of the productivity different from the technical progress.