Modern wireless networks tend to employ more antennas to profit as much as possible from MIMO techniques. But as the number of antennas increases, the problem of antenna mutual coupling will affect the performance of MIMO systems currently operating in wireless networks such as zero forcing (ZF) and Max-SNR precoders. This research treats the issue of mutual coupling resulting from the electromagnetic interaction between adjacent antennas and its effect on the work of the ZF and Max-SNR precoders in MIMO systems. The results showed a clear decrease in the performance of the two precoders at small spacing between the antennas. It also showed the possibility of reducing the problem of antenna mutual coupling by increasing the antenna spacing which is not always available in MIMO systems.