The detection, localization, and tracking performance of multiple input-multiple output (MIMO) radars with widely separated antennas is investigated and compared with that of multistatic radar systems. A multiple-hypothesis (MH)-based algorithm is proposed for multitarget localization for the case where extended targets with multiple spatial reflections become unobservable in certain transmitter-receiver pairs. A particle filter (PF)-based algorithm is then proposed to handle dynamic multitarget tracking. Finally, simulation results are provided to demonstrate the relative capability of MIMO radars in localizing and tracking extended targets under various signal-to-noise ratio (SNR) conditions compared with multistatic radars.