This article uses Ajzen's theory of planned behavior to build an entrepreneurial intention questionnaire (EIQ) and analyzes its psychometric properties. The entrepreneurial intention model is then tested on a 519-individual sample from two rather diverse countries: Spain and Taiwan. EIQ and structural equation techniques have been used to try to overcome previous research limitations. The role of culture in explaining motivational perceptions has been specifically considered. Results indicate EIQ properties are satisfactory and strong support for the model is found. Relevant insights are derived about how cultural values modify the way individuals in each society perceive entrepreneurship.