This chapter analyzes the relationship between social entrepreneurship and institutional factors in the Spanish context, using institutional economics as the conceptual framework. To achieve this objective, we use models of logistic regression analysis, and specifically Rare Events Logistic Regression (RELOGIT), based on data from Global Entrepreneurship Monitor (GEM). The main findings demonstrate that informal institutions, such as fear of failure and perception of entrepreneurial skills, and formal institutions, such as access to funding and education, influence social entrepreneurial activity in Spain. Likewise, our data supports that informal institutions are more important than formal ones for promoting social entrepreneurship. The study contributes advancing theory on the field of social entrepreneurship and also could be useful for the design of government policies on the promotion of social entrepreneurial activity.