This report on Czech participation in international comparative socioeconomic survey research is primarily aimed at providing useful information on the sources of data available for secondary analysis in sociology. Mainly the infrastructural role of international projects is examined in this regard. The author provides a complete list of multinational continuous sample-survey programmes that have public domain databases and include Czech data, and he also presents a selection of projects in other areas (one-time international surveys, comparative official statistics, events data, etc.). A significant proportion of all current social research in the Czech Republic involves participation in international projects. In academic research most of the available survey data that are suitable for monitoring change are from international projects. However, for some topics and types of research - for example, socio-economic household panel research, and research on migration, communication or the ageing of the population -there is little or no comparable data available.