In this paper, we evaluate the performance of filter bank-based multi-carrier with offset quadrature amplitude modulation (FBMC/OQAM) for the multi-user multiple-input multiple-output (MIMO) uplink in the presence of timing and frequency misalignments. In such a scenario, multiple access is achieved by assigning groups of sub-carriers to user nodes. The nodes are equipped with multiple antennas, and different frequency selective channel models are considered. In addition, a comparison with orthogonal frequency division multiplexing with the cyclic prefix insertion (CP-OFDM) as the currently widely used multi-carrier scheme is presented. The greater robustness of FBMC/OQAM against a lack of synchronization in the time and the frequency domain compared to CP-OFDM is shown via extensive numerical results.