Myotis blythii is a species complex. Within the Lesser Mouse-eared Bat there are at least three distinct groups which may be split as full species. The type locality for M. blythii is India which means that (if splitting) the European species becomes M. oxygnathus, for which the common name tends to be Monticelli's Mouse-eared Bat. The third split species is the Maghreb Mouse-eared Bat M. punicus.
The subspecies still retained within M. blythii after the splits - ancilla, lesviacus, and omari - may also be separable as species.