This research was carried out in Seeds Testing Laboratory, Crop Science and Plant Breeding Department, Faculty of Agriculture/UNESP, Botucatu, SP, Brazil), with the purpose of studying the effects of reduction in the imbibition period of seeds as well the temperature increase on the electrical conductivity test, for evaluating the vigor of peanut seeds (Arachis hypogaea L.). Treatments were set in a completely randomized design outline fatorial 3x5. The electrical conductivity of three peanut seed lots (sieve 20) of cv. Tatu was evaluated on three hour imbibed seeds (75ml of deionized water) at 20, 25, 30, 35 and 40°C using four replications of 25 pure seeds. The electrical conductivity was recorded in a condutivimeter and the results were expressed in µS/cm/g. Seed moisture contents, before and after the evaluation of the electrical conductivity, seed germination, first count of the germination, speed of seedling emergence and field emergence were detected. The electrical conductivity test was effective to detect the lower quality lot, after three hour of imbibition period; however, the highest performance was attained at 40°C.