The goal of the paper is to unravel the geo-economic complexity of regional agglomeration economies. For this one, the spatial focus is on the western region of Santa Catarina. The main result of cross-referencing the literature with empirical research data was to break the stereotype that the region under analysis is specialized purely and simply in agro-industrial production. In fact, it is a complex, specialized and diversified geo-economic dynamic; given the overflow of agro-industrial capital into other productive sectors, such as machinery and equipment, mechanical metal, renewable energy, meat production technologies, real estate investments and others. This led to the identification of four agglomeration economies with differences and similarities from a production point of view: Chapecó and Xanxerê, Concórdia and Joaçaba, Videira and Caçador and, finally, São Miguel do Oeste. Methodologically, the research considers three steps: 1) bibliographic and data collection; 2) fieldwork and technical visits; 3) organization, cross-referencing and qualification of the data collected. Keywords: Geo-Economics Complexity; Agglomeration of Economy; West of Santa Catarina.