While mnemonic systems have been taught and used for hundreds of years, virtually all of the experimental research into such systems has been conducted since 1965. This paper describes four mnemonic systems, all of which rely heavily on visual imagery, and summarizes research conducted on the performance values of each system. The link system, the simplest of the systems, aids serial recall by associating items with each other in a chain of associations. The loci system, the most ancient of the systems, aids recall by associating items with prememorized mental images of locations. The peg system aids recall by associating items with a prememorized series of concrete nouns (pegwords). The phonetic system, the most complex, substitutes consonant sounds for digits, to allow for coding numbers into words and for constructing extensive lists of key words to be used in the same manner the loci and pegwords are used. The paper concludes that mnemonic systems can make enough of a contribution to memory to warrant their mastery and use and that research into such systems should be continued. (Author/RL)