The density and biomass of epiphytic macroinvertebrates onEichhornia crassipes, Nuphar luteum, Panicum hemitomon, Paspalidium geminatum, Ceratophyllum demersum, Utriculariaspp. andHydrilla vertlcillatawere determined In Orange and Henderson lakes, Florida, during December 1982 and February, April, June and August 1983. Density and biomass of epiphytic macroinvertebrates ranged from 6 to 9714 individuals kg−1wet weight of plant and 2 to 3118 mg dry weight kg−1wet weight of plant, respectively, among macrophyte species. The quantities of epiphytic macroinvertebrates were greater on floating and submergent plants than on emergent plants. Abundant invertebrate taxa included Hirudinea, Gastropoda, Amphipoda, Odonata, Trichoptera, and Diptera. There were significant (P <0.05) temporal variations in the abundance of invertebrates; however, consistent temporal trends were not evident.