A cold bath technique was developed to determine diapause status of boll weevils, Anthonomus grandis grandis Boheman. Nondiapausing boll weevils from a laboratory culture were compared with boll weevils reared under diapause inducing conditions. Boll weevils were exposed to five freezing temperatures of 0.0, -2.5, -5.0, -7.5 and -10.0 C for 2, 4, 6, and 8 consecutive hours. The tests were conducted twice, once in November-December, 1992 and again in March, 1993. Significantly more diapausing boll weevils survived, as compared with nondiapausing boll weevils, at all temperatures. A high percentage of diapausing and nondiapausing boll weevils survived temperatures of 0.0, -2.5, and -5.0 C, while a low percentage of diapausing and nondiapausing boll weevils survived temperatures of -10.0 C. A 6-hour exposure to -7.5 C most effectively discriminated between diapausing and nondiapausing individuals. Under these conditions, 68.8% of the diapausing weevils survived as compared with only 2% of the nondiapausing weevils.