A survey of the community of helminths in Emydura krefftii Gray in central and northern Queensland was undertaken. Then a detailed study of Sychnocotyle kholo Ferguson, Cribb and Smales, 1999, a newly described aspidogastrean parasite of E. krefftii, was conducted. The principal aim of this study was to examine the life history, fine morphology and phylogenetic relationships of this species. Specimens of Emydura krefftii were sampled from six coastal catchments from Cooktown to Bundaberg in northern and central Queensland. Concurrently data were collated on the community structure of helminths of E. krefftii. To examine the life history of S. kholo, molluscs were collected and examined for juvenile aspidogastreans from areas sampled for turtles and S. kholo eggs were collected from the faeces of collected turtles. The study of morphology of this helminth involved staining whole mounts and sections for light microscopy for gross morphology and examination of organ systems. Scanning electron microscopy was used to examine the outer surface of the worm in detail. For fine morphology of organs, transmission electron microscopy and confocal microscopy were applied. Finally characters were identified for a phylogenetic analysis and a data matrix was constructed and executed with Phylogenetic Analysis Using Parsimony (PAUP) software.