The spawning behavior of the Atlantic silverside, Menidia menidia, was studied at two sites on the North Edisto River estuary in South Carolina. Spawning M. menidia deposited their eggs on three types of substrates including: (1) the lower stems of cordgrass plants, S. alterniflora, (2) detrital mats and, (3) exposed cordgrass roots along erosional scarps. Spawning behavior during egg deposition and fertilization was similar for all three spawning substrates. Females released eggs by a rapid fluttering motion of the posterior half of the body. A similar movement accompanied release of milt by males. Behavior of fish just prior to spawning was modified to insure deposition of eggs at locations that provided protection from thermal and desiccation stresses.