Compost has been shown to improve soil physical and chemical properties when incorporated into the soil; however, little information is available about effects that topdressing compost onto turfgrass has on soil properties or water quality. The objectives of the study were to evaluate the effects that topdressing Kentucky bluegrass with composted manure has on: (i) soil chemical properties, (ii) soil physical properties, (iii) nutrient runoff, and (iv) nutrient leaching. Established plots of Kentucky bluegrass (Poa pratensis L.) were topdressed with composted manure at 0, 33, 66, and 99 m3 ha-1, three times in two years. A rainfall simulation study was conducted, and soil was sampled in 10 cm increments to the 50 cm depth. Compost increased P,K, Fe, and Mn concentrations in the 0-10 cm depth. Compost applications also raised the soil EC in the 0-10 cm depth by 18-32%. However, this increase in soil EC did not negatively impact turf quality. Compost application of 99 m3 ha-1 reduced surface soil (0-3 cm) bulk density by 5.3% and increased water retention by an average of 14.2% over all tensions tested. Concentrations of total nitrogen, nitrate, total phosphorus, total dissolved P, and Ortho-phosphates in runoff were not different among treatments. However, compost treatments increased mean NH4-N concentrations in runoff by about 45% compared to the control. In addition, there were no differences in soil NO3-N or available P (AB-DTPA) levels below the root zone (30-50 cm), indicating no difference in leaching potential. Our data indicate that topdressing composted manure onto established turf improved soil nutrient concentrations and soil physical properties without increasing nutrient runoff or leaching, with the exception of increased NH4-N levels in runoff.