Literature on the institutional adoption of information technology (IT) can be classified into two approaches, one emphasizing rationalistic goal-oriented behavior and the other focusing on external forces. These approaches, however, are not necessarily mutually exclusive. Organizations adopt IT both to achieve efficiency and in response to a variety of environmental and internal pressures. Consequently, there is a clear need for an integrated model that incorporates both institutional pressures and goal-oriented behavior. We develop, operationalize, and empirically test a model that explains the intention of small and medium-sized enterprises (SME) brokerages to adopt electronic trading systems (ETS). This model integrates the rational factors driving goal-oriented behavior with the internal and external pressures to which these brokerages are subjected. The model is parsimonious, yet explains 67% of the variance in the intention to adopt ETS. The theoretical and practical implications of this model are discussed.