Human resources are recognised as being key to the creation, commercialisation and diffusion of innovation. Among them, doctorate holders are not only the most qualified in terms of educational attainment, but also those who are specifically trained to conduct research. In 2004, the OECD launched a collaborative project with the UNESCO Institute for Statistics and Eurostat aimed at developing internationally comparable indicators on the labour market, career path and mobility of doctorate holders. This Working Paper presents the second edition of the technical guidelines used in the framework of the Careers of Doctorate Holders (CDH) project. The technical guidelines are composed of: i) the methodological guidelines; ii) a core model questionnaire and instruction manual; and iii) the output tables used for reporting data at the international level and related definitions. This second edition builds on the experience resulting from the first large scale data collection, which was based on the first edition of the technical guidelines released in 2007. In addition to a number of basic adjustments, it proposes new ways to measure post-doctoral positions and types of mobility, including international mobility. The current draft is the result of discussions among the members of the CDH expert group. Its aim is to provide guidance to countries that wish to implement the project at national level.