In the course of an empirical study with 208 students from Lüneburg, Ajzen's 'Theory of Planned Behavior' is used to explain individual start-up intentions. After a description of the research approach, results of the study will be presented. Hierarchical regression analyses show that attitude, social norm and perceived behavioral control contribute substantially to the explanation of start-up intentions. The use of the indirect measurement model reveals a significant influence of attitude and social norm on the estimation of the intention (R²= 0,543), whereas index based measurements show that the start-up intention is significantly influenced by all three constructs (R²=,446).The additional contribution of background factors to the explanation is marginal.