Haemocytes of the Pacific beetle cockroach, Diploptera punctata (Esch.), are described and figured as they appear in vivo and in stained blood films. Although the haemocyte complex in this species is comprised of the same main categories as found commonly in other cockroaches, it is somewhat unusual due to morphological specialization among one category, the granular haemocytes. Most of the cells in this category are similar to those in other species, but some contain distinctive vesicles of mainly proteinaceous material, some are ovoid and contain spherule-size granules, and some are large, fusiform cells that are actively amoeboid in vivo. The other main categories, prohaemocytes, plasmatocytes, and spherule cells are fairly typical.