Recent literature on social innovation highlights its conceptual ambiguity and fragmentation. Addressing this call, this paper examines how social innovation initiatives or projects fit in the sustainable development goals and in what way empowers citizens and communities towards serving their needs. Thus, 210 cases studies were analyzed across three domains in which social innovation can be understood: content, process and empowerment. For this a content analysis was performed. The results obtained demonstrate that the sustainability challenges more frequently addressed where those promoting social support at a regional level. Non-governmental organizations emerge as the main social innovators, in order to address the identified social needs. The results highlight the generation and provision of new services as the main output of the innovation process. Using the SDGSs as a classification system of social innovation projects seems to be very suitable.