Species of the tettigoniid genus Isophya are indicators of biogeographical history and also measures of the state of nature conservation in the Carpathian Basin and in Europe. We surveyed the occurrence and habitat preference of five species (I. camptoxypha, I. costata, I. kraussii, I. modesta, I. modestior) living in the Transdanubian region (the western part of the Pannonian biogeographical region) to determine the potential for the preservation of the insects and their habitats. Statistical analysis shows the optimal habitats of I. camptoxypha are patches of herbaceous plants and lower shrub layers within natural forests dominated by tall or medium-height broad-leafed (mainly dicotyledonous) mesophytic forest species. For I. camptoxypha smaller clearings, and the forest ecotones containing the aforementioned plant species are suboptimal, and populations of the insect species occur there at a significantly lower density. Present-day I. costata find optimal conditions in highly natural, loess grasslands or mesophytic hayfields and steppe grassland–hayfield transitions rich in plant species. This same Isophya species at a lower density can be found in grasslands having suboptimal conditions, but with a similar habitat physiognomy, adjoining the abovementioned grasslands or developing through their slight degradation. Based on a critical literature review and our own sampling, we also comment on the habitat choice of a further three species (I. kraussii, I. modesta, I. modestior).