Abstract
The side-necked turtle Hydromedusa tectifera commonly inhabits the tributary streams of the Rio de La Plata and occasionally is found in brackish waters within the estuary of the Rio de La Plata. Few studies have been conducted on its parasitic fauna, especially in Argentina. In the present work Amphiorchis sp. is registered for the first time in a freshwater turtle, expanding the knowledge about the specificity of the genus that until now was considered inhabiting only marine turtles.