The present research focuses upon new businesses which are started from scratch. The theories of reasoned action and planned behavior are used to formulate hypotheses concerning self-employment intentions and subsequent entry into self-employment. The hypotheses are tested using longitudinal data from 297 Norwegian business founders. The results suggest that salient beliefs concerning self-employment determine attitudes toward self-employment, that attitude and subjective norm determine intentions to become self-employed, and that intentions to become self-employed determine actual entry into self-employment. The findings strongly support the theory of reasoned action, but provide no support for the extension of the theory represented by the theory of planned behavior.