Abstract-- Performance analysis of Multiple-input Multipleoutput (MIMO) Orthogonal Frequency-Division Multiplexing (OFDM) systems with carrier frequency offset and channel estimation errors is considered in this paper. Based on the analysis of the Inter-Carrier-Interference (ICI) and Inter-AntennaInterference (IAI) due to the residual frequency offsets, the average Signal-to-Interference-and-Noise Ratio (SINR) is derived. The bit error rate of equal gain combining (EGC) and maximal ratio combining (MRC) with MIMO-OFDM is analyzed, and an infinite-series approximation for the bit error rate is derived. Simulation results illustrate the accuracy of the theoretical analysis.