Display omitted •Trichoderma spp. were screened for anti-Phytophthora activity.•Trichoderma atroviride/petersenii (KACC 40557) showed the best anti-Phytophthora activity.•Trichoderma metabolite treatment caused plant hormonal and transcriptional changes. Trichoderma species are well-known biological control agents. In this study, metabolites from 128 Trichoderma isolates were extracted from liquid cultures using ethyl acetate and tested for their activities against seven Phytophthora isolates. Following preliminary analysis, eight Trichoderma isolates were selected for further tests. Among them, the metabolites from Trichoderma atroviride/petersenii (KACC, Korea Agricultural Culture Collection, 40557) and Trichoderma virens (KACC 40929) showed the strongest inhibitory activities against Phytophthora isolates. Treatment with KACC 40557 extract inhibited Phytophthora growth, induced defense-related genes, and caused plant hormonal changes during Phytophthora infection in the detached leaves of pepper and tomato plants. Our results showed the potential for use of Trichoderma metabolites as biological control agents against Phytophthora pathogens.