We examined nocturnal microhabitat preferences of the endangered Growling Grass Frog Litoria raniformis in lotic and lentic environments in southern Victoria, Australia. Data were obtained during surveys of six wetland sites during the summer of 2003. At all sites the observed distribution of frogs amongst microhabitat categories differed from their availability, as assessed by sampling of random points. Frogs were located most often on bare soil, bare rock or leaf litter when on land, and on floating, submergent and emergent vegetation in aquatic situations. Non-metric multidimensional scaling and analysis of similarities (ANOSIM) were used to compare the structural attributes of microhabitats used by L raniformis to those of random points. In both the riparian and aquatic zones of the study sites, microhabitats used by these frogs differed from random points in their degree of vertical structural complexity. Whilst our data may be biased by the observability of frogs in different microhabitats, this study suggests that structurally open microhabitats are an important component of the habitat of L raniformis. The ecological basis for this result is discussed, as are implications for our understanding of the species' habitat requirements.