The seeds of barley, oat, rye, and two varieties of wheat were studied during wetting thereof with special respect to changes in their mass and dimensions. Two levels of wetting were used: 6-h wetting close to the end of imbibition, and 24-h wetting close to the start of germination. The results of these experiments show that the measured quantities can be well described by the Gaussian distribution. Gaussian distribution is applied for description of the wetting effects that can be well approximated also by a second-degree polynomial of the initial state. Even though an increase in the mass, length, width, and thickness was the main effect of wetting, opposite trends in some dimensionally dependent cases were also observed. Drying of the wetted specimens led to a state that differed only slightly (less than 1%) from the initial state. Among the dimensional characteristics, the highest changes were observed in the grain length.