The effect of a new sulfonylurea herbicide, DPX-T9595, on the growth and yield of cotton varieties 'DES 119' and 'Stoneville 506' were investigated for a Bosket and Dundee very fine sandy loam soil near Stoneville, MS in 1987 and 1983. DPX-T9595 was applied from 1 to 2 oz./A preemergence (PRE) and from 0.06 to 0.5 oz./A postemergence over-the-top (POE). Cotton heights and number of nodes were not affected by DPX-T9595 at these rates. Cotton injury was not above an unacceptable level with DPX-T9595 at < 2 oz./A PRE, < 0.5 oz./A POE on 6- to 8-leaf cotton, or < 0.25 oz./A on 2- to 4-leaf cotton. DPX-T9595 shows promise for POE control of a number of difficult-to-control broadleaf weeds, including cocklebur, hemp sesbania, and morningglory species, without adversely affecting cotton growth and yield.