The ecology of free-living nematodes in various natural salinity-affected habitats (viz. Mc Murdo and Taylor valleys of Antarctica, estuaries, deep Sea, Aral Sea bottom, halophytic tuft grass nematodes of golf courses, hyper-arid and hyper-saline oasis and desert soils, coastal entomopathogenic nematodes, stylet-bearing nematodes of mangroves of Sundarban and salinity relations of parasitic nematodes in agricultural systems (hatching of their eggs, larval survival, and infectivity of host plants, as studied by various nematologists, are briefly overviewed.