Abstract-In this paper, we investigate the serial-search-based initial code-acquisition performance of direct-sequence code division multiple access (DS-CDMA) employing multiple transmit/ multiple receive antennas when communicating over uncorrelated Rayleigh channels. We characterize the associated performance trends as a function of the number of antennas. It is demonstrated that, in contrast to our expectation, the achievable correctdetection probability degrades in our typical target operational E c /I 0 range as the number of transmit antennas is increased. When maintaining a given total transmit power, our findings suggest that increasing the number of transmit antennas results in the combination of the low-energy noise-contaminated signals of the transmit antennas, which ultimately increases the mean acquisition time (MAT). However, it is extremely undesirable to increase the MAT when the system is capable of attaining its target bit-error-ratio performance at reduced signal-power levels, as a benefit of employing multiple transmit antennas.Index Terms-Code acquisition, direct-sequence code division multiple access (DS-CDMA), multiple transmit/multiple receive antennas (MTMR), serial search.