The penetration depths (PDs) of 81 different organic liquids into uncracked dry cement mortar were measured by a suction test at ambient pressure. The physicochemical properties of the liquids (viscosity (eta), surface tension (sigma), density (rho), partition coefficient (logP), and molecular volume) were correlated with their penetration depth at normal pressure. It was found that viscosity has the main impact on the penetration. It could be shown by dimensional analysis that the penetration depth at ambient pressure is proportional to the parameter (sigma rho/eta(2))(1/4). Furthermore, a device to measure the penetration at high pressure Lip to 50 bar was set up. It was experimentally found that the natural logarithm of the PD at constant time is approximately proportional to the natural logarithm of the applied pressure. A method was elaborated to extrapolate the penetration depth at normal pressure from one single high-pressure measurement. The advantage of this technique is the significantly shorter measurement time for the high-pressure test of 15 min up to 1 h compared to the usual tests at normal pressure which require 72 h.