The Centre for Science and Technology Studies of Leiden University organized the 11th International Conference on Science and Techno-logy Indicators 8 – 11 September in Leiden. Science and technology indicators have become an increasingly important instrument for science policy and research management. The assessment of strengths and weaknesses of a country’s science system, ranking, benchmarking and classification of universities, finding excellence in research, identification of emerging and often interdisciplinary research themes, measuring knowledge transfer between academia and industry – all these examples show the value of S&T indicators for users.