This study has been conducted in the district of Massaciuccoli (lake, marsh and reclaimed areas with drainage channels) in Tuscany region (Central Italy). The aim of the research was to detect the presence of parasites in fishes, in particular of Opisthorchis felineus, which causes an important zoonosis. Between 2010-2012, the health status of 381 fishes was monitored, morphometric characteristics were determined, and parasites were searched for and identified. Of the 381 examined fishes, 189 were free of parasites while 192 were infected, among them 91 presented multiple infections. Opisthorchis felineus was not found in any of the examined fishes.