The kinetics of crystal growth of ferroelectric Rochelle salt have been studied by applying an electric field of 2–1000 V/cm between the upper face of a crystal and an electrode immersed in the water solution in contact with the lower part of the growing or dissolving crystal. It has been found that the rate of growth decreases while the rate of dissolution increases by about 10% above and belowTcof 24°C of the crystal at 900 V/cm. The results are discussed theoretically. Similar experiments under the application of a uniaxial pressure showed a less significant effect, while a vibrating alternating pressure of about 8 kg/cm2, and 50 cycles/sec showed a significant increase of the rate of growth by about 50%.