The quantitative evaluation of the anisotropy of ceramic wall products based on its capillary properties was performed in the paper. Measures characterizing the material's ability to absorb liquids in a direction of a product's molding and perpendicularly were experimentally determined, and then liquid transfer coefficient was calculated using these indicators and applying a simple, yet accurate and theoretically justified method developed by the Authors. Results of theoretical and experimental studies provide a basis to conclude that the anisotropy of ceramic building products has a significant impact on the indicators characterizing the capillary moisture transfer process. The anisotropy coefficient defined as the ratio of the moisture diffusivity in a direction of product molding to the same coefficient, yet in perpendicular direction, can reach value of 7.5. Ignoring such explicit anisotropy of a product at calculating the moisture content of walls can lead to significant errors in liquid transport calculations. Comparison of mean conditional radii of capillaries involved in liquid transport calculated using proposed equations with data from mercury porosimetry indicated that porosimetric data cannot be applied to characterize the porosity structure of ceramic building materials in a direction perpendicular to the product molding.