Abstract: This paper presents a replacement procedure for cache memories. The procedure is essentially a fuzzy algorithm that makes use of 18 rules to select the cache block to be replaced. These rules are primarily a function of three parameters: age, frequency of usage of a cache block and the global hit ratio of the cache system. Computationally, the proposed algorithm calculates a replacement index for each cache block and the block with the highest replacement index is selected as the victim. The performance of this fuzzy procedure is compared with the traditional replacement algorithms such as Least Recently Used (LRU) and First-In-First-Out (FIFO). Our simulation results indicate that the proposed algorithm is a strong contender to the traditional counterparts. Unique feature of the proposed algorithm is its flexibility; that is, one can always improve its performance further by fine-tuning the rules.