Butterflies of the genus Maniola are known for their large morphological variation, at the inter- as well as intraspecific level. Given the overlap in wing-patterns, habitat selection, and geographic distribution of various Maniola species, genitalia morphology is sometimes the only possibility to tell specimen apart. In this paper we describe diagnostic characters to distinguish different Maniola species by means of their genitalia. Included is also the first detailed description and illustration of the genitalia apparatus of the Sardinian endemic Maniola nurag. Further, we describe two Sardinian individuals with intermediate characteristics between Maniola nurag and Maniola jurtina, and propose that they are hybrids. Further, we shortly discuss the justification of the species status for the island endemics Maniola chia and Maniola cypricola.