When traditional marketing practices are unfit for small and medium enterprises, entrepreneurs have to put aside traditional principles and shift them to new innovative thoughts and actions, such as entrepreneurial marketing (EM). For this study, exploratory analysis was employed to analyze entrepreneurial marketing strategies used in knowledge-based companies of Tehran province by considering the aspects of coopetition. Whilst digital marketing is playing a significant role in SMEs, our research has targeted EM, which is recognized as the crucial factor in such businesses launched in Iran. The research model was developed using the grounded theory paradigm model approach. The study population consisted of experts working in knowledge-based companies located in Tehran Province, of whom 15 individuals were selected as the sample using purposive sampling. The data were collected using semi-structured interviews. In the first step of the grounded theory approach (open coding), the researcher used the data obtained from the in-depth interviews to identify and analyze the main research categories, including opportunity focus, coopetition, proactiveness, innovation, customer intensity, value creation, pioneering, risk management, networking, and resource leveraging. The paradigm model approach was then adopted in the next step (axial coding) to identify effective factors. Finally, as a research innovation, a general model was designed to develop a theory of entrepreneurial marketing strategies. From the developed model of strategies, some analytic recommendations are put forward for the SMEs, such as companies being more active in the development of entrepreneurial marketing strategies and introducing newer products and services than their competitors, if they wish to survive in a competitive market, whilst corporate managers are urged to probe continuously the unknown needs of their customers as key to their entrepreneurial marketing strategies.