Comparisons of allozymes at 17 loci were made among 11 species of the littorinid genus Littoraria and two species of an outgroup genus, Nodilittorina, as an independent test of relationships within Littoraria, currently based on anatomical traits. Genetic identities between species were generally low, averaging 0.59 within and 0. 40 between the major clades of the anatomically-based phylogeny, three of which are recognized as subgenera. Neither phenetic nor phylogenetic analyses of the allozymes revealed strongly supported, distinct subgeneric groupings. Nevertheless, there was broad consistency with the existing proposed phylogeny, and the discrepancies are largely for taxa of uncertain placement based on either set of traits. Thus, the allozyme comparisons increase confidence in the current interpretations of relationships within this genus, but do not resolve the questionable relationships.