The article is part of a special issue of Survey Research Methods on „Recent Methodological Advances in Panel Data Collection, Analysis, and Application” (Vol. 17, No. 3), gust edited by Tobias Wolbring and Sabine Zinn. It presents a methodology for operationalizing and measuring precarious careers for cross-country comparative research. We conceptualize precarious employment as sequences of three types of adverse labour market experiences: non-employment, frequent job separations, and low income from work. These experiences are a common element in existing definitions of employment precarity, and may be studied using available panel survey data over a broad range of countries. We consider these experiences to be valid indicators of labour market disadvantage across countries with differing institutional arrangements. In order to capture the sequence of employment statuses and periods of low income with a single metric variable, we draw on recent developments in the field of sequence analysis. The proposed Cross National Precarity Index (CNPI) is a composite measure that takes into account: the level of complexity of a career sequence; the occurrence and intensity of adverse labour market experiences over the course of a career; and the location of these states in a given sequence. We illustrate the behaviour of the CNPI index and its components using theoretically meaningful examples of hypothetical careers and empirical data from panel surveys conducted in Germany (SOEP) and the US (NLSY97).