In order to improve knowledge of Neotyphodium-likc fungi in European grasses, microscopic detection of endophytic mycelium was achieved in living grasses and in seeds. Samples of grasses were gathered near permanent pastures or along paths in France (93 samples, 13 genera, 22 species). Typical convoluted mycelium was found inside leaf sheaths of four genera, especially in Festuca and Lolium spp. The results suggest that endophytes were present most often in the southern regions where plants may suffer from summer drought. Endophytes were looked for in 489 seed samples (63 genera, 237 species) received from 24 European botanical gardens. Neotyphodium was found in seeds of only six genera (22 species), especially in Festuca (15 species) and Lolium (three species). No endophytic mycelium was found in the other 215 species, although other work had demonstrated the presence of the fungus in 39 of the species analysed. Neotyphodium-likc mycelium was detected for the first time in Festuca juncifolia, F. trachyphylla, F. vaginata, F. pseudodalmatica, F. rupicaprina, F. arenaria, Vulpia ciliata and Micropyrum tenellum. Further studies are needed for the correct identification of the Neotyphodium species observed.