Repeat applications of biosolids and manure to cropland increase the risk for P enrichment of agricultural runoff. Composting improves handling and storage characteristics of manure and biosolids, which permits their application to land at times that are more environmentally sound. We conducted field research in 2003 and 2004 on a Fauquier silty clay loam (Ultic Hapludalf) to compare the effects of continuous (since 1999) annual applications of composted and uncomposted organic residuals on P runoff characteristics. Biosolids compost; poultry litter-yard waste compost; uncomposted poultry litter; and commercial fertilizer were applied based on estimated plant available N. An unamended control treatment was also included. The crop rotation was corn (Zea mays L.)-cereal rye (Secale cereal L.). The amendments were analyzed for water soluble P and EPA 3050 P, Ca, Fe, and Al. End of season soil samples were analyzed for Mehlich 3 P, EPA 3050 P, water soluble P, degree of phosphorus saturation, soil C, and bulk density. We applied simulated rainfall in fall 2004 and analyzed runoff for dissolved reactive P, total dissolved P, total P, total organic C, and total suspended solids. Compost treatments significantly increased soil C, decreased bulk density, and increased all forms of extractable P. The concentration of dissolved reactive P, total dissolved P, and total P in runoff was highest in the compost treatments, but the mass of dissolved reactive P and total dissolved P was not different among treatments because infiltration was higher and runoff lower in compost-amended soil. Improved soil physical properties associated with composted poultry litter application decreased the total loss of total P and total suspended solids.