Southern stem canker of soybean was detected on more than 10 cultivars in 3 and 13 locations in Itapua and Alto Parana prefectures in Paraguay, respectively. Symptoms and signs on the diseased soybean plants were identical with those reported for the disease previously. Morphology and characteristics of the pathogen both on the host and artificial media agreed with the descriptions of Diaporthe phaseolorum f. sp. meridionalis (anamorph: Phomopsis phaseoli f. sp. meridionalis). About 150 isolates were obtained from the diseased soybean plants. Soybean plants inoculated with some of the isolates showed symptoms typical of the disease 2-3 weeks after inoculation. It was shown for the first time that the disease occurred in Paraguay.