A herbicide resistance weed control system that utilizes naturally occurringmutations to ACCase inhibiting herbicides could greatly improve selectivity and control of grassy weeds in turf. Knowledge regarding the presence of these mutations in grasses is needed to guide development. This research surveyed 24 species of warm-season, cool-season, and grassy weed species for the presence of mutations at amino acid positions 1781, 1999, 2027, 2041, 2076, 2088, and 2096. These species were also subjected to three rates, 0, 400, and 1200 g a.i. ha-1 of fenoxaprop herbicide. Resistance mutations were found at position 1781 in three of 24 species surveyed (Festuca ovina, Festuca rubra, and Poa annua). Nine species were resistant to fenoxaprop (Agrostis capillaris, Festuca ovina, Festuca rubra, Lolium multiflorum, Lolium perenne, Paspalum dilatatum, Poa annua, Zoysia japonica, and Zoysia matrella). These results will aid in the development of an ACCase resistant system for turfgrass.