A finite-length optimized-delay multi-input-multi-output (MIMO) mean-square-error decision-feedback equalizer for space-time block-coded transmissions over multipath-fadingchannels is presented. Alamouti's space-time block code with two transmit and two receive antennas on a typical urban EDGE channel is taken as a case study. We propose a combined equalization and decoding scheme under the constraint of linear processing complexity (no trellis search) at the receiver. Performance comparisons are made with the single-transmit/single-receive antenna case and the case of MIMO feedforward linear equalization only with no decision feedback.