In this paper, we consider a 2 x 2 Multiple-Input Multiple-Output (MIMO) system using Full-Diversity Full-Rate (FDFR) code. To obtain full diversity gain from FDFR code, ML receiver should be inevitably used. However, ML receiver has very high complexity problem. Therefore, we proposed an efficient receiver for a 2 x 2 MIMO system with FDFR code. The proposed receiver has very low complexity compared to ML receiver and provides full diversity gain. In the threshold parameter, γo = 2.2, there is the reduction effect of about 46 ∼ 48% from the view point of the number of multiplication and very small SNR gain loss within 0.2 dB compared to ML receiver.