This paper aims to identify and analyze the barriers to innovation that influence the innovation capability of Portuguese firms. The focus is on the study of entrepreneurial innovation capability, specifically the technological innovations made by the firm in relation to product innovation. It is nowadays recognized that while talking about competitive advantages of a firm, a region or even a country, the innovation subject occupies an important place. We live in an age of globalization and strong competitiveness in which firms more frequently need to make the difference to their competitors, so innovation is the path to follow. The conceptual model that is proposed makes use of the system innovation approach, as well as the networks and inter-organisational relationships approach. The selection of these approaches is due to the adequacy they present for the study of the determinant factors of entrepreneurial innovative capability. In this research, the innovation concept is defined as a non-linear linear, evolutionary, complex and interactive process between the firm and its environment. Thus, it is intended with this essay to develop a theoretical support based on current reference approaches, corroborated by an empirical support which allows identifying and analysing the restraining factors of innovation activity and of entrepreneurial innovative capability. Nevertheless, it should be stressed that in the present study, the entrepreneurial innovative capability is associated with product innovation. The database is extracted from the Community Innovation Survey 4 (CIS 4). According to the data granted by the "Observatorio da Ciencia e do Ensino Superior" (OCES), that was conducted by EUROSTAT on distinct European countries. In order to identify the significant determinants of entrepreneurial innovative capability, a logistic regression is performed. The most important barrier perceived in the study is the economic factor: lack of external financial sources. Other confirmed barrier is reasons for not innovate: unnecessary because there isn't market/demand for the innovation. The analysis suggests that several barriers to innovation have influence on the innovation capability of Portuguese firms.