Phenobarbital was pulverized by recrystallization from glycols and their derivatives, and correlation of difference in the degree of pulverization with the solvent was studied. The crystalline form of the pulverized phenobarbital were also examined. The degree of pulverization of phenobarbital by recrystallization from glycols and their derivatives decreased with increase in the carbon atoms in the hydrophobic chain of these solvents. Two different solid phases (hydrate and form II) of pulverized phenobarbital were examined, and the hydrate (with 1 mol H2O) was transformed into form II (anhydrate) on being kept in a desiccator under a reduced pressure at room temperature.