The sweet potato [Ipomoea batatas(L.) Lam.] cultivars ‘Jewel’, ‘Centennial’, ‘Caromex’, and breeding lines ‘W-70’, ‘W-152’, and ‘Tinian’ (PI 153655) were evaluated for metribuzin [4-amino-6-tert-butyl-3-(methylthio)-as–triazin5(4H)-one] tolerance in greenhouse and field studies. Tinian was the most tolerant line. Its yields were not reduced by 2.2 kg/ha metribuzin in the field. Jewel, Centennial and W-152 were intermediate in response to metribuzin, and W-70 and Caromex were most susceptible. Regression analyses indicated a high correlation between the response of sweet potato cultivars to 0.5 ppm metribuzin incorporated in a potting mix in the greenhouse and their response to 1.1 kg/ha metribuzin applied after transplanting in the field.