In this paper, a delay-variation effect under alpha-particle strikes is evaluated in content-addressable memories (CAMs). The particle strikes into transistors induce a current-pulse signal that causes the delay variation, resulting in a timing error, called a soft-delay error (SDE). The delay variations in two different CAMs designed in a 90nm CMOS technology are simulated in NS-SPICE using a charge-injection model that generates a current-pulse signal. The SDE effects are discussed, where one of the CAMs is a traditional 9-transistor-cell CAM and the other one is a magnetic-tunnel- junction (MTJ)/MOS hybrid CAM that operates based on a multiple-valued current-mode logic. The simulation results show that there is a trade-off between the amount of current (thus power dissipation) and the SDE effects in the MTJ/MOS hybrid CAM.