Helminth parasites of woodmouse Apodemus sylvaticus were studied from May 1993 through to June 1994 on the River Avena (Calabria, southern Italy), which, as other Mediterranenan rivers, is dry for most of the year. Trapping sites were located in three different habitats of the river: slopes, shores and the riverbed. A total of 106 animals was captured and screened for the presence of helminths. Five endoparasitic species were detected: Corrigia vitta, Rictularia proni, Heligmosomoides polygyrus, Syphacia stroma and S. frederici. Four helminth species were recorded from the riverbed and shore sections, whereas only H. polygyrus and S. frederici were found on the slopes. Syphacia frederici occurred at every trapping site. The total prevalence was 25.5% and total mean intensity was 27.2 parasites/mouse. No statistical significant difference was found for both the prevalence and mean intensity of infection between either habitats or sexes, suggesting that, from the point of view of the helminth community, the study area should be considered as a single habitat.