Stylommatophoran land snails and slugs generally mate by shell-mounting or face-to-face. Although phylogenetic evidence suggests that the mating position has remained more or less constant throughout the evolution of most lineages, other aspects of mating behavior and associated reproductive characters are highly variable. Along with other gastropods, therefore, stylommatophoran land snails and slugs could be particularly useful in trying to understand sex and sex allocation theory in hermaphrodites. It is often difficult, however, to compare mating behavior in different species because the literature is difficult to access or reports have not been formally published. Here we review studies on the mating behavior of snails and slugs, with the additional aim of creating a central access point and database for use as a resource by those interested in stylommatophoran mating behavior. As we maintain the database, updated versions will be made available at  http://www.molluscs.org.