In the context of fish parasites, helminths and protozoans are the main fish parasites present in all types of inland waters. However, among the helminthes, monogeneans have greater deleterious impact on the freshwater aquaculture systems. Monogeneans are flatworms (Platyhelminthes), ectoparasitic, hermaphrodite and attached by special posteriorly positioned attachment organs to their host's skin or gills. The present study explains the occurrence, distribution and pathology of monogenetic gill parasites in rohu from the three ponds of Tripura, India. Host-pathogen-environment interaction in farmed Indian major carp, rohu (Labeo rohita) were also been mentioned in the literature. Temporal and spatial variations in the gill monogeneans were also investigated to know the abundance of monogeneans at different time intervals. Spatial distribution of monogeneans was performed to investigate the distribution pattern in different parts of the gill. Attempt was taken to find out any relation between some patho-physiological parameters with monogeneans. Different classical forms of monogenean induced histopathological changes of gill were also prominent.