The anatomy and histology of the female and male reproductive and digestive systems of Rhizoglyphus robini are described. The female reproductive system consists of paired ovaries and oviducts, accessory glands, oviporus, receptaculum seminalis, and terminal bursa copulatrix. Paired testes and vasa deferentia, sperm sac, ductus ejaculatoris, accessory gland and penis constitute the male reproductive system. The female and male reproductive systems are similar in their basic anatomy to those of other acarids but differences exist between R. robini and other species in the family Acaridae. The digestive system resembles the typical acarid form consisting of a pharynx, resophagus, ventriculus, paired caeca and Malpighian tubules, colon, and rectum.