Corrugated cardboard packaging which is used in the distribution of fruit and vegetables, during the transport of products between manufacturer and consumers was exposed to the various atmospheric conditions, like relative humidity and air temperature. Distribution channel usually refers to a longer stay of fruits and vegetables in a variety of refrigerated vehicles during transport as well as refrigerated storages. And also includes short-term exposures to outdoor atmospheric conditions when reloading. To preserve the quality of fruits and vegetables, combination of low temperature with high relative humidity was maintained inside refrigerated vehicles. Such environmental parameters with respect to hygroscopic properties of corrugated cardboard packaging (they absorb water readily) having an extremely adverse effect on its mechanical properties, especially to the compression strength of corrugated cardboard, ECT. Paper packaging in conditions of high relative humidity absorbs moisture in order to achieve equilibrium with the surrounding air. In accordance with the subject of this paper, different double wall corrugated cardboards were tested and the dependence of strength was explored in correlation to the moisture content of the double wall corrugated cardboards. Tested samples were conditioned for 24 hours in various conditions of relative humidity and temperature after which was measured the moisture content of corrugated cardboard and its compressive strength, ECT (Edge Crush Test). The results of testing were presented using the statistical method of regression analysis. The research confirmed a negative relationship between the value of ECT and the moisture content of corrugated cardboard. Moreover, throughout the paper was confirmed that in addition to the moisture content of the corrugated board a big impact on its strength characteristics also bears the quality of of corrugated case materials used in the production of the corrugated cardboard.