This technique has the advantage of not depending on the probability distribution of the data. The objective of this study was to estimate the sample size required for the individual electrical conductivity test in sunflower seeds. Seven lots of sunflower seeds were used: 3 lots of the cultivar Hélio 250, 2 of the BRS 323, and 2 of the BRS 324.The individual electrical conductivity test was conducted with each lot of 400 seeds, and the sample size was determined by the seed number from which the amplitude of the 95% confidence interval (AIC 95% ) was less than or equal to 15, 20, 25, 30, and 35% of the mean estimate. The sample size of 483, 257, 172, 115, and 85 seeds is sufficient to estimate the average of the individual electrical conductivity of sunflower seeds with an AIC 95% equal to 15, 20, 25, 30, and 35% of the mean estimate, respectively, for all lots and soaking periods.