The reproductive system of the fire ant queen consists of the ovaries, the oviducts, a spermathecal duct, spermatheca, spermathecal glands, uterus, vagina, bursa, and vulva. Although this system is similar to that of many insects, numerous differences are reported. Follicle sizes within the ovarioles show abrupt changes between the proximal and distal regions of the vitellarium. These follicles are followed by nurse cells which increase in size with the growth and development of the oocyte. In the enlarged calyx are found numerous flagellumlike structures which arise from papillae throughout most of the calyx lumen. These structures are lacking on the ventral wall of the calyx and throughout the rest of the oviduct. A muscular fold exists on the floor of the uterus, similar to that found in the honey bee, Apis mellifera L. The significance of this fold is discussed. The spermathecal duct arises anterior to a dorsoventrally elongated uterus and is supported by a rigid and. modified cylindrical structure immediately anterior to its junction with the spermatheca. A uterine pouch exists above the junction of uterus with spermathecal duct. Most of the lining of the reproductive system is simple columnar epithelium, although some of the cells become cuboidal, pseudostratified, and even squamous in various regions. Surrounding the epithelial lining throughout most of the reproductive system are layers of striated muscle. A membranous intima is found within the lumen of the posteriormost regions of the system.