[This is the second of two reprints (1994 and 1999) of the 1992 Australian Museum publication] Species keys using external characters are given for the 33 microchiropteran bat species recorded from south-eastern Australia, except for the five species of the taxonomically chaotic genus Mormopterus, and female Eptesicus. The key is designed for use by non-specialists. Identification criteria, synonyms and broad distributional limits are summarised in individual species accounts. Substantial taxonomic uncertainty affects two thirds of the species in south-eastern Australia. Field identification of a significant proportion of species remains problematical because reliable external, diagnostic characters are not known. Consequently, easy or accurate field identification is not possible for many species. The need to retain voucher specimens to confirm identifications is emphasised.