This paper investigates the business value of IS/IT investments in the Financial Services Sectors (FSS) in Australia using a case study methodology to develop and refine a conceptual model of the relationship between IS/IT investment and organisational performance. The conceptual model has four main components, IS/IT investment, organisational performance, considerations for strategic information systems planning and managerial effectiveness. A case study of a credit union indicates support for components of the conceptual model. Further, the analysis reveals the existence of intermediary factors, operations, product delivery, customer service and staff. It is concluded that directing IS/IT investments to these areas, particularly when it is done in concert, is most likely to have a positive impact on organisational performance. Lastly, debate on the issue of an IS/IT investment threshold and its applicability to organisations is presented.