The aim of this paper is to examine interorganisational cooperation in view of the theory of organisational entrepreneurship. The fundamental question behind the paper is whether collaboration could be perceived as entrepreneurial behaviour and, furthermore, whether opportunities could be pursued through collaboration and creating new alliances. Such a thesis is confronted with competitive aggressiveness that is proposed as one of dimensions of entrepreneurial orientation. The concepts of collaborative entrepreneurship is described. Indications to include collaboration into the entrepreneurial theory are suggested, and some ideas of conceptualisation and operationalisation are discussed.