Two cotton trials were conducted in northwest Florida in 1995 and one in 1997 in fields infested with the southern root-knot nematode. Treatments in each trial consisted of 4 rates of Telone II and Temik 15G, and a control. The Telone II treatments were applied with a single chisel in the row 2 or 3 weeks prior to planting. Temik 15G treatments were applied in the furrow at planting. The control and Telone II treatments also were treated with an in the furrow Thimet 15G at planting to control thrips. Plot rows were 36 inches wide and 4 rows x 25 feet long. Treatments were replicated 6 times in a randomized complete block design. Six postharvest soil cores (1-inch-diam) were taken from each plot to 10 inches deep and composited. Nematodes were extracted from a 100 cm3 subsample from each plot by the centrifugation-sugar flotation technique. Lint yield was determined by harvesting the center 2 rows of each plot. Costs were estimated as the sum of material and application costs per acre. Because of method of application, Temik was not assigned application costs, only material costs. Telone II application costs included the cost of Thimet plus an additional $0.74 per acre (prorated Telone II equipment costs). Yields of the Telone II treatments were consistently and significantly greater than those of the control. Almost all Telone II treatments outperformed the Temik treatments, but not all differences were statistically significant. Analagously, Telone II treatments accounted for the greatest partial net returns.