The presence of cyanogenic glycosides was determined in 70 plant species from the campus of the State University of Londrina, PR, Brazil, and a further 45 plant species from the Forestry Reserve on the Doralice Farm in Ibiporã, PR, Brazil. Of the vegetative species from the State University of Londrina, 7.1% showed cyanogenic glycosides: Manihot esculenta (Euphorbiaceae), Passiflora edulis (Passifloraceae), Macadamia ternifolia (Proteaceae), Prunus persica (Rosaceae) and Beloperone sp (Acanthaceae).The first four species were considered to be potentially cyanogenic in the field. From the Forestry Reserve on the Doralice Farm, the plant species with cyanogenic glycosides were: Holocalix balanseae (Caesalpinaceae), Nectranda megapotamica (Lauraceae), Trichilia casareti (Meliaceae), Trichilia elegans (Meliaceae) and Rapanea umbellata (Myrsinaceae), making 11.1% of the total species analyzed. Only Holocalix balanseae was considered to be potentially cyanogenic in the field.