Chiroptera, commonly known as bats, show a huge diversity in diets which may have shaped the sizes of olfactory bulbs in bats with distinct diets. To study whether olfaction impacts the dietary diversification in bats, we identified all olfactory receptor (i.e. OR) genes with a homology-based approach from the published genome data of ten species of bats, and assigned each gene into an OR gene subfamily. Our results showed that bats also possess 13 monophyletic subfamilies of OR genes, as reported in other mammals. Furthermore, within the suborder Yinpterochiroptera, we identified three subfamilies (OR1/3/7, OR2/13, OR5/8/9) with significant expansions in fruit-eating bats compared to insect-eating species, which suggested that the three gene subfamilies are associated with the recognition of ripe fruit smell. Together, this work recovered the evolutionary history of OR genes in bats using a genome-wide analysis, and identified some OR genes that may be specialized for the recognition of ripe fruit smell in fruit-eating bats. These results highlight the importance of olfaction in dietary selection for animals.