A new ammonia fungus, Coprinopsis austrophlyctidospora, is described from Nothofagus and Pinus forests in New Zealand and from Eucalyptus forest in Australia. In ecology and macro-morphology, this species is similar to the Northern Hemisphere species C. phlyctidospora, but the new species differs in morphological characters of the basidiospore, i.e., in having a plage, more minute surface warts, and the smaller size of the basidiospore.