In Germany, over a third of all new hires are based on fixed-term contracts. However, the effects of fixed-term contracts on individual career paths and the employment conditions of fixed-term workers have not been sufficiently dealt with in previous research. This project seeks to provide evidence using appropriate micro-econometric methods.Concerning career paths, we identify the determinants of transitions into and out of fixed-term employment. In particular, we consider the effects of age, gender, previous experience of unemployment or atypical employment and the family context. In a second step, the long-term effects of spells in fixed-term employment on subsequent unemployment, labour force participation and employment stability are at the centre of attention. The leading question in this part of the project is whether and under which conditions fixed-term contracts facilitate the transition into regular employment, or whether they lead to continued job insecurity for the individuals concerned (in particular, the unemployed, persons at the start of their careers, and those returning to the labour market after a spell of non-employment). Among the indicators for employment conditions of fixed-term workers, we use remuneration, access to further training, the number of absences from work due to sickness, fertility decisions and different dimensions of job satisfaction.The empirical studies are based on two representative data sets, the German Socio-Economic Panel (GSOEP) and the BIBB/IAB survey. We seek to determine the causal effects of fixed-term contracts under plausible assumptions. To this end, two control groups are used to which career paths and employment conditions of fixed-term workers can be compared. The first comprises employees in regular employment, while the second control group consists of individuals not currently employed. In the latter case, we explore how employment opportunities are affected if an unemployed person accepts a fixed-term contract rather than continuing to search for a job out of the state of unemployment.