Within the theoretical framework of Entrepreneurship Studies, this article investigates the thriving immigrant-based street market system in Alicante, Spain. Entrepreneurship research clearly has illustrated that the success of legitimate entrepreneurial endeavours is determined by a complex variety of factors that involve supply and demand, risk vs. return and opportunity vs. need, among others. Based upon field observations, interviews and a detailed survey conducted during the summers of 2005 and 2006, our investigation of the small business street vendor system in Alicante illustrates that these entrepreneurial factors also define and affect the illegal enterprises established by a largely undocumented immigrant population. Despite the apparent simplicity of the street vendor network, both the wholesale and retail systems in Alicante are highly complex and structured, and they work to minimise risk to street entrepreneurs while providing greater economic returns to a large and highly diverse population.