Description: Since 2000 the promotion of lifelong learning has become an issue of growing importance within the European Union, accompanied by an increasing interest in the recognition of informally and non-formally acquired competences. As a consequence in Germany the ProfilPASS-project has been initiated. The ProfilPASS is a guided self-assessment tool which includes a biographical portfolio and a documentation of abilities and competences. Usually, a counsellor supports the individual's assessment. The ProfilPASS is a joint project of three German research institutes (DIPF, DIE, ies). It is supported by the 16 German Bundesländer and funded by the German Federal Ministry of Education and Research and the European Social Fund. This paper presents the results of an evaluation study, which focused mainly on whether the users regard the instrument as helpful in finding out about their competences and enhancing their self-reflection and self-confidence. Another focus was to explore whether particular user groups can be identified that profit more or less from working with the ProfilPASS. Methodology: Members of a heterogeneous sample of more than 300 users were asked to complete an evaluation questionnaire. This questionnaire assessed (1) demographic user variables (e.g. age, gender, education and migration), (2) psychological user variables (personality, values and goals, life satisfaction), (3) process variables (e.g. frequency and form of guidance), and (4) outcome variables (e.g. benefit, overall satisfaction with ProfilPASS). In a variable-oriented multiple regression approach, the different variable blocks (1-3) are compared in their predictive value for the outcome evaluation criteria. In a person-oriented approach, differences between specific user groups are identified using recursive partitioning as an exploratory data mining procedure. Conclusions: About 60% of the ProfilPASS users have a positive general view of the instrument, whereas 30% were undecided, and only about 10% of the users were not satisfied. In a joint prediction the three blocks account for 54% variation in the criterion, for the process variables block the explained variance is about 12%, demographic user variables explain about 18%, whereas the psychological variables explain 32%. Recursive partitioning revealed that adolescents who are still in school rate the benefit of the ProfilPASS lower than adults. Adult participants valued the ProfilPASS more when they were guided by a counsellor. In summary, especially people not satisfied with their personal and occupational situations as well as those with little formal qualification benefited from working with the ProfilPASS.