I investigate the mechanisms through which a cluster policy can enhance entrepreneurship defi ned as new venture creation. The paper is based on the study of a cluster policy ('BioRegio') that strongly simulated new fi rm creation in biotechnology in Germany after 1996. The process induced by BioRegio at the territory level is analyzed over a ten-year period (1995-2004). I identify a three-step social mechanism through which a cluster policy can enhance entrepreneurship. The presented results strengthen the literature on cluster policies and clusters on the specifi c issue of entrepreneurship: four main contributions are suggested. [ABSTRACT FROM AUTHOR]