Nyctalus lasiopterus is mostly associated with old-growth forest stands, where it roosts in woodpecker holes or other tree cavity types, but it may also occur in more open habitats, as far as suitable roosts are available. It may occasionally roost in the dry leaves in the upper part of palm trees, bat boxes, buildings or rock crevices (reviewed in Ibáñez and Juste 2022).

The species covers very large home ranges to forage in open spaces, moving up to over 90 km from their roost to the foraging sites and hunting at 124–367 m above ground with a maximum height of 1,659 m, as shown by GPS tracking (reviewed in Ibáñez and Juste 2022).

The diet includes a range of arthropods, especially moths, but other groups (dipterans, beetles, neuropterans) may be locally important. The most prominent feature, however, is given by the consumption of passerine birds during migration, probably taken on the wing, that account for > 50% of the diet during the postnuptial bird migration period (Dondini and Vergari 2000, Ibáñez et al. 2001).

A long-distance migrant in central and Eastern Europe, N. lasiopterus may be present year-round in certain areas of western Europe (e.g., Russo et al. 2023) or show an altitudinal migration pattern, with the two sexes segregating according to altitude.

The Giant Noctule (Nyctalus lasiopterus) is mostly a European species with a reduced presence outside the continent. Its range extends from the Atlantic coast of Iberia to the Middle Volga provinces in Russia, including the Mediterranean and much of Central Europe. Recorded in Corsica, Sicily (a single nineteenth-century record), Cyprus, Giglio, and Mljet and Kornat, in the Kornati archipelago, Croatia (reviewed in Ibáñez and Juste 2022). There are also three records of vagrant bats for Belgium (N. Bouillard pers. comm.). The European range appears, overall, fragmented. The AOO and EOO have not been estimated, but based on the available locality records, they are expected to greatly exceed the threshold for a threatened category. The species has been recorded from the sea level up to foraging areas at a height of 2,666 m asl (reviewed in Ibáñez and Juste 2022).

Outside Europe, it occurs in North Africa (Morocco and Cyrenaica in Libya), Anatolia, and the Caucasus (Russia and Georgia). Vagrant individuals have been recorded for Iran and Kazakhstan.

Nyctalus lasiopterusis protected by national legislation in most range states as well as by the Eurobats Agreement and Bern Convention, where these apply. It is included in Annex IV of the EU Habitats Directive. According to the latest (2013-2018) art. 17 reporting done under the Habitats Directive, the species conservation status in the Alpine and Mediterranean biogeographic regions is unfavourable-inadequate, in the Black Sea and Continental biogeographic regions it is unfavourable-bad and is unknown in the Atlantic and Pannonian biogeographic regions. The most critical action to take to preserve N. lasiopterus is the conservation of unmanaged forests, or, in logged forest sites, the maintenance of large live trees, decaying trees or snags bearing suitable cavities used for roosting. Small forest islands in agricultural landscapes may play an important role in supporting giant noctule populations and warrant special protection.