Abstract: Lernaea cyprinacea, a parasitic cyclopoid copepod, is reported parasitizing sailfin molly Poecilia latipinna breeders, cultured in the Center of Advanced Study in Marine Biology, Parangipettai (India). The fish were severely infected on their body surface with the highest number of 38 parasites per host. Feeding and reproductive activities, including spawning, stopped following parasitic infection. The parasites are females unsegmented, sub-cylindrical shaped and 20 mm in length. They are provided with paired appendages including prominent egg sacs. This is the first report on their occurrence in the cultured ornamental fish P. latipinna, in India. Lernaea infection was successfully controlled by gradually changing the water salinity to 10‰.