The kinetics of the crystallization of metals from the melt under superfast cooling velocities realized in the treatment of the materials by ultrashort laser pulses is investigated. The size distribution function for crystalline phase nuclei is analytically found within the framework of the classical kinetic equation in case of superfast temperature changing. The average number of particles in the crystalline nuclei and relative volume of the crystalline phase are determined as functions of thermodynamic and laser treatment regime parameters. Good agreement is observed with experimental results for ultrashort laser pulses induced micro- and nanostructures production.