It has been over two decades since group support systems (GSS) emerged on the information technology (IT) scene. GSS have now been commercialized and are present in an increasing number of domestic and international contexts but only lightly studied in real organizational settings. A criticism of studies has been that many of the organizations involved had a vested interest in the outcome that extended beyond that which would normally occur in a typical organization. An additional challenge has been made with respect to the generalizability of field study results across corporate and national cultures. This paper compares and contrasts findings from International Business Machines (IBM) and Boeing Aircraft Corporation in the US with those from two European companies: Nationale-Nederlanden (NN), the largest insurance firm in the Netherlands and European Aeronautic Defense and Space company, Military division (EADS-M). Attention is given to aspects of efficiency, effectiveness, and user satisfaction as well as group dynamics.