Efficient strategies to control the bronze bug Thaumastocoris peregrinus Carpintero and Dellapé (Hemiptera: Thaumastocoridae) are unavailable, but Cleruchoides noackae Lin and Huber (Hymenoptera: Mymaridae) parasitizes eggs of this pest. The parasitism and number of parasitoids that emerged from the eggs of T. peregrinus were evaluated in the laboratory and from eggs of this pest collected in the field in an area of approximately 2 ha. Collections were done 1 yr after the first release of C. noackae to check for field establishment of this parasitoid in eucalyptus plantations in Minas Gerais State, Brazil. The emergence of C. noackae was 53 and 52% from eggs parasitized in the laboratory and in the field, respectively. This natural enemy was recorded for all sampling points from the field collections, which were up to 10 km from the place it had been released. The C. noackae establishment in the field, and the potential for biological control of T. peregrinus by this parasitoid were confirmed.