The predominant aim of this study was to contribute to the methodology in research on work trajectories as essential element of the life course in adulthood. Data on the labour market attachment of a population cohort (n = 1005) from age 30 to age 42 were collected with a questionnaire. We applied trajectory analysis in order to define different attachment tracks. According to the information criteria, six tracks were discerned: in addition to those who are in permanent employment (high-level attachment), in temporary employment (medium-level attachment) and out of work (poor-level attachment) throughout early middle age, we were able to define subgroups that move from temporary to permanent employment (strengthening attachment) or vice versa (weakening attachment), and also some who enter working life and attain permanent employment at a relatively high age (delayed attachment). On average, attachment was high and strengthened with time, indicating that no major de-standardization of employment occurred during the follow-up years (1995-2007) in the studied labour market and age cohort. Given longitudinal data with at least ordinal scale variables, the applied trajectory analysis may be recommended as a "method of choice" in clustering the diverse and non-standard work-life courses into a meaningful set of tracks. (C) 2011 Elsevier Ltd. All rights reserved.