Switch and stay diversity combining is shown to offer substantial complexity reduction at the cost of modest performance degradation compared to systems with selection diversity. In this work, the performance of multiple input multiple output (MIMO) systems employing switch and stay combining at the receiver is studied. Only 2 antennas are assumed to be present at the receiver. A novel switching algorithm is proposed and an upper bound on the pairwise error probability (PEP) is derived. Based on this upper bound, the optimal switching threshold is derived and it is shown that the system can achieve full diversity when the optimal switching threshold is used. The switching rates have also been derived to characterize the switching burden on the system. Simulation results have also been included to corroborate our results.