Effects of the alkanolamine salt of (2,4-dichlorophenoxy) acetic acid (2,4-D) and sodium salt of 4-hydroxy-3,5-diiodobenzonitrile (ioxynil) upon seedlings of Chewings fescue (Festuca rubra var. commutata Gaud.), Park bluegrass (Poa pratensis L.), and Highland bentgrass (Agrostis tenuis Sibth.) were evaluated in growth room and field studies. In the former, injury to Park bluegrass from both 1 and 3 lb/A applications of 2,4-D was severe with pronounced but less marked effects on fescue and bentgrass. Results were similar from applications shortly after emergence and after clipping the grass. Negligible injury was caused by 1 lb/A of ioxynil. In the field, ioxynil gave better weed control than 2,4-D when applied at a seedling height of 1 inch. No injury was caused by ioxynil. Although 2,4-D reduced yields from early clippings, there was marked recovery, even at 3 lb/A. No treatments significantly affected plant stand.