Proximity ranging is very important in many applications. Ultrasonic sensors have proven to be very cost effcctive tools for this purpose. Most of the currently available time-of-flight based acoustic proximity ranging systems use the conventional matched filter based time delay estimation approaches to measure short distances between prox-irnity objects. However, in the presence of strong and closely spaced secondary echoes, the aforernentioned matched filter based algorithms tend to fail or suffer from severe pertformanee degradations due to their poor resolutions. In this paper, a computation-ally efficient time delay estimation algorithm, referred to as Multi-PEARS (Multi-echo Parameter Estimation for Acoustic Ranging Systems), is described for the joint proxim-ity range estimation and secondary echo mitigation. The effectiveness of the proposed algorithm is demonstrated by both numerical and experimental examples.