Widespread concern over eutrophication has focused attention on pathways of phosphorus loss from agricultural lands. To-date, limited information exists on the role of drainage ditches in the export of phosphorus from manure-amended fields in coastal plain settings. Since 2001, we have monitored two ditches exiting the University of Maryland Eastern Shore's research farm, formerly a commercial poultry operation with a long history of litter application at high rates. Monitoring data indicate that ditches play a key role in agricultural phosphorus losses. In 2004, phosphorus losses exceeded 10 kg/ha. Storm flow accounted for 70-98% of annual phosphorus losses from the ditches, with large contributions of dissolved phosphorus (up to 55% of annual total phosphorus losses). Comparison of ditch monitoring data with runoff data from adjacent fields suggests that resuspention of ditch sediments is an important source of particulate phosphorus in storm flow. Results highlight the potential for improved management of ditches for water quality protection.