Purpose. Scientific productivity is most often measured by quantitative indicators that commonly include bibliometric parameters for evaluation of scientists and scientific institutions, as well as scientific journals. This paper presents an overview of the legal basis for the quantitative evaluation of scientific productivity in Croatia, with an emphasis on the role of libraries in the mentioned process. Furthermore, the development of quantitative evaluation of scientific productivity in Croatia has been presented, on the example of the National and University Library in Zagreb, which provides bibliometric services to the Croatian academic community at the national level. Approach/methodology. The research is based on an overview of the current and proposed laws and regulations in the fields of librarianship and higher education and science in Croatia, related to the evaluation of scientific productivity. In addition, a more detailed analysis of the Ordinance on Academic Promotion and Advances Requirements, as the legal foundation for evaluating scientists and their productivity in Croatia, is made. The analysis of the use of bibliometric services provided by the National and University Library in Zagreb is presented in the second part of the paper. Findings. The analysis of laws and regulations in the areas of librarianship and higher education and science in Croatia has shown that the role of academic and research libraries in the process of evaluating scientific productivity is insufficiently defined. The role of libraries in the evaluation process is most commonly defined at the level of the parent institutions, while at the national level it is mentioned only by the new Ordinance on Academic Promotion and Advances Requirements from 2017. Originality/value. This paper can serve as a basis for further research and development of bibliometric services and quantitative evaluation of scientific productivity in Croatia and strengthening the role of libraries in these processes.