Switch-level simulation has become a common means of validating the behavior of MOS circuits. In this paper, we present a new cache-based simulation method that significantly reduces the cost of subnetwork evaluation during switch-level simulation. The method speeds up simulation by as much as a factor of two. While caching may require additional memory, the structural hierarchy can be exploited to quickly identify subnetworks computing identical functions, merge their cache tables, and significantly reduce the memory requirements.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">></ETX>