PurposeThe purpose of this paper is to identify how different factors of antecedents and processes affect the outcomes of an internship, measured in terms of competency development.Design/methodology/approachThe authors used an internship questionnaire designed for the University of Tartu in Estonia. Responses were obtained from 178 students across different disciplines – humanities and the arts, social sciences, natural sciences and medicine – who had recently taken an internship. Based on current academic literature, the authors create a three-level model: antecedents-processes-outcomes. The antecedents and processes were both differentiated into three factors and tested with a structural equation model.FindingsThe model demonstrates that there are different antecedents that have an effect on internship outcomes, but these only work through internship processes. For example, the objective of the internship and clarity of instructions will only have a positive effect if there is relevant support from the supervisor at the employing company and if the student can use the knowledge and skills gained at university.Research limitations/implicationsThe study is based on survey data filled in by students, i.e. based on self-perception. Based on the results of the study, the authors claim that an active role and initiative-taking by students in finding suitable internships should be further encouraged.Originality/valueWhilst previous studies have used a two-level model of internship (or a three-level model for students satisfaction as an outcome) the authors create and test a three-level model measuring competency development as the outcome of an internship.