Five level-bottom communities in Kingston Harbour, Jamaica, are described. These are a Spiochaetopterus community of the polluted Harbour Head, a Chaetopterus community of the deep Inner Basin, an Armandia-Alpheus community of the shallow, low-salinity Hunts Bay, a Lumbrineris-Diplodonta community of the deep Outer Basin, and a Branchiostoma community of the sand shoals. Diversity increases from inside to outside the harbour along pollution and salinity gradients. The low-diversity community is indicative of severe environmental stress conditions and is similar to some communities in other parts of the world. The high-diversity community reflects favourable conditions and is typical only for certain tropical environments. The effect of reduced salinity in Kingston Harbour is greater seasonally than tidally.