Himantoglossum adriaticum H. Baumann is a long-lived perennial orchid with an adriato-mediterranean distribution. The species-level separation of this species from the more geographically widespread H. hircinum has only recently been confirmed via a combination of molecular and morphometric techniques, which are further developed here. To provide a comprehensive overview of its autecology we integrated previously published information with extensive unpublished data derived mainly from populations in the Keszthely Hills of Hungary. In this paper we assess the distribution, habitat preferences, life history and seed germination (ex situ and in situ) of H. adriaticum, with special emphasis on its reproductive biology.