In this paper, we investigate the effect of multiple input multiple output (MIMO) systems on the performance of the multicarrier direct sequence code division multiple access (MC DS-CDMA) system operating over independent identically distributed (i.i.d) η–μ flat fading environment in terms of average error probability and average channel capacity. We derive the instantaneous signal to interference noise ratio (SINR) at the output of the receiver. Hence, based on moment generating function (MGF) approach, we obtain the probability density function (PDF) of the instantaneous SINR. Closed form expressions of average error probabilities for the system are developed and expressed in Appell’s and Lauriccella’s hypergeometric functions. Furthermore, we achieve exact expression of average channel capacity for the system. Finally, we validate our results using Monte Carlo simulation technique and also compare with those already available in the literature.