Field experiments were conducted in which submerged aquatic vegetation (SAV) was either removed or added to tidal freshwater marsh creeks and nekton was sampled on adjacent marshes with flume nets. These experiments were designed to determine whether the presence of SAV in tidal creeks influences the abundance of fishes and grass shrimp Palaemonetes pugio Holthuis on contiguous marshes. In experiments where SAV was removed from tidal creeks, the number of grass shrimp on adjacent marshes decreased, but the average density of fishes, mostly mummichogs Fundulus heteroclitus (Linnaeus) and banded killifish F. diaphanus (Lesueur), was not reduced. The abundance of grass shrimp increased on marshes where artificial SAV was added to adjacent tidal creeks without natural SAV, but the abundance of fish did not increase. The density of marsh plants and marsh elevation were investigated as additional factors that could influence the abundance of nekton on the marsh surface, but we found no evidence that these factors were important. We conclude that the proximity of SAV and the depth of adjacent tidal creeks are the most important factors that influence the abundance of nekton on tidal freshwater marshes.