The community composition of rockpool fish on the southwestern coast of Yaku-shima Island, southern Japan, in the northwest Pacific was investigated by sampling of 22 rockpools and recording the range of vertical heights (a total of 76 sampling events from May 2009 to February 2010). A total of 72 species belonging to 19 families were collected from the study site. This species richness is the highest recorded of similar studies undertaken worldwide, reflecting the highest diversity of coastal fishes in the western Pacific. Increases in species richness due to transient and accidental visitors increased the total number of species in the lower vertical zones. Variations in the vertical distribution pattern of the resident and transient species suggests habitat partitioning and/or physical preferences for a particular habitat of each species. Color images of rockpool fish recorded at the site and a list of all the voucher specimens are provided.