This paper investigates the efficiency level of Unions of Agricultural Cooperatives (UAC) and Investor-Oriented Firms (IOF) in Greece. Data have been collected over a period of six years for UAC (1995-2000) and of five years for IOF (1995-1999). Financial analysis results were used with the help of 3SLS technique in a four equation simultaneous model in order to estimate those parameters, which would determine the efficiency level of the UAC and the IOF in Greece.