The objectives of this study were to investigate the relationship between electrical resistance and various parameters and to quantify the changes in this relationship for several varieties of apples. The objects of testing were apples of three varieties, i.e., McIntosh, Spartan and Starkrimson. The universal bridge was used for the resistance measurements. The tests were carried out on both specially prepared samples and on whole apples. Apple resistance varied from 2.1 to 6.4% and sample resistance was higher, i.e., 7.9-16.5%. Compared to the green sides, the resistance of on red sides was 0.7-2.2% higher for apples and 4.2-8.3% higher for samples. Resistance increased with measurement time. The slope of the line was computed for each variety tested at its harvest time. The change in resistance per unit of time was significantly different and declined with harvest time. The resistance, averaged for 20 apples increased progressively during harvest time by as much as 20%. The change in resistance during harvest time for tested varieties differed significantly. This is contrary to the normal pattern of a gradual softening of the flesh as fruit matures on the tree. Spartan and Starkrimson had lower resistance than McIntosh which corresponds inversely to firmness. Correlations of electrical resistance with pressure test values were highly significant for all cultivars.