Dispersal by waterbirds and wild mammals is known to be important for maintaining biodiversity among wetlands. Cattle are known to be important seed dispersers in terrestrial habitats, however the role of cattle in plant dispersal among wetlands is poorly known. We analysed the potential for the dispersal of aquatic plants (seeds, diaspores and whole plants) by cattle (Bos taurus) through endozoochory in Neotropical wetlands. Ten fresh faecal samples per site (total 30 samples), were collected in three farms of the Pampa region, southern Brazil, between September and November of 2023. A total of 982 propagules and whole plants from 37 wetland plant taxa, belonging to 14 angiosperm and two fern families, were reported. Ten of these taxa are aquatic, seven terrestrial and 19 grow both in water and on land. Viability was confirmed for seeds from 10 angiosperm families, and for 26% of all seeds tested. Our results suggest cattle provide an important ecosystem service for wetland biodiversity in grassland areas through seed dispersal.