We have measured the pressure dependence of the solid phase epitaxial growth rate of self‐implanted Si (100) by using theinsitutime‐resolved interferometric technique in a high‐temperature and high‐pressure diamond anvil cell. With fluid argon as the pressure transmission medium, a clean and perfectly hydrostatic pressure environment is achieved around the sample. The external heating geometry employed provides a uniform temperature across the sample. At temperatures in the range of 530–550 °C and pressures up to 3.2 GPa (32 kbar), the growth rate is enhanced by up to a factor of 5 over that at 1 atmosphere pressure. The results are characterized by a negative activation volume of approximately −3.3 cm3/mole (−28% of the atomic volume). These results show a significantly weaker pressure dependence than does the previous work of Nygrenetal. [Appl. Phys. Lett.47, 232 (1985)], who found an activation volume of −8.7 cm3/mole. The implication of this measurement for the nature of the defects responsible for crystal growth is discussed.