Innovative social entrepreneurship (ISE) is a topic of recent interest in research. The knowledge of the determinants of ISE and the characteristics of the innovations created by them is still limited. Therefore, the present document aims to contribute to this knowledge; specifically, it explores the determinants of the innovative behavior of ISE, during its process of creation and growth, and discusses the nature of such innovations (type, novelty, scope and impact) created throughout that process. Based on a case study of a paradigmatic Mexican social organization, we argue that these determinants are divided into: internal (characteristics of the individual entrepreneur and model/strategy of the organization); and external (context/environment). These determinants are causally associated with different stages of the abovementioned process and with certain attributes of the innovations developed. In addition, it is suggested that ISE innovation has a strong intangible and non-technological component, mainly in business model innovations, but also in its operating model (based on social inclusion).