— In this paper, a low-complexity high-performance detection algorithm for multiple input multiple output (MIMO) channels with severe delay spread is proposed. This algorithm performs iterative data detection over factor graphs which apply an independence approximation as well as a Gaussian approximation. It is shown that this algorithm achieves a near-optimum BER performance for coded MIMO systems with severe delay spread. The computational complexity of this algorithm is strictly linear in the number of transmit antennas, the number of receive antennas, and the number of non-zero channel coefficients.