The results are given of surveys of the natural enemies attacking insect pests of soyabean carried out in the municipality of Guaiba (Rio Grande do Sul) in 1978-1980. Leaf-feeding pests were heavily parasitised and attacked by fungi. Some 78.4-83.3% of the larvae of Plusia spp. were controlled by natural enemies, as were 48.2-59.7% of those of Anticarsia gemmatalis Hb. The main enemies of Plusia spp. were tachinids, Litomastix truncatella (Dalm.), a nuclear polyhedrosis virus and the fungi Nomuraea rileyi and Entomophthora gammae. A. gemmatalis was parasitised by tachinids, the ichneumonid Microcharops bimaculata (Ashm.), a nuclear polyhedrosis virus (Baculovirus anticarsia) and the fungi N. rileyi and Zoophthora radicans (E. sphaerosperma). Larvae of the borer Epinotia aporema (Wlsm.) were parasitised by a braconid of the genus Agathis. Pentatomids were heavy attacked by tachinid parasites, especially Eutrichopodopsis nitens Blanch., and by the fungus Beauveria bassiana, which also attacked chrysomelids and curculionids. none