The bronze bug Thaumastocoris peregrinus Carpintero & Dellapé (Hemiptera: Thaumastocoridae) is a pest of Corymbia and Eucalyptus. Thus far, there are no effective control methods for this pest in commercial plantations. A study of the reproductive tract could provide basic strategies for controlling this insect. T. peregrinus females and males, of different ages, were obtained from mass rearing and analyzed using light microscopy. The male reproductive tract has a pair of testes with three globular follicles isolated by a peritoneal sheath, and two pairs of well-developed mesadenial tubular accessory glands. The female reproductive tract includes a pair of ovaries, each with two meroistic telotrophic ovarioles, opening into two long lateral oviducts, which joints in a short common oviduct. This common oviduct ends in a large and folded, thick-cuticle lined bursa copulatrix. Eggs with embryos in the stages of anatrepsis, catatrepsis, and post dorsal closure were found in the reproductive tract of females. The reproductive tract of T. peregrinus males and females are similar to those of other Thaumastocoridae, but differ in the number of ovarioles per ovary in its females.