We here present, metal nanocrystal (NC) formation statistics (size, density, occupancy or area coverage) on different high dielectric constant (high-K) materials which may be used as tunnel dielectric or intermetal dielectric in flash memory devices. Four important high-K materials viz. SiO 2, Al 2O 3, HfO 2 and Si 3N 4 are chosen for this purpose and the nanocrystal formation statistics has been found to be strongly dependent on dielectric. Among all the four dielectrics, smallest size nanocrystals with largest density are obtained on Al 2O 3 dielectric while on HfO 2 bigger size nanocrystals are formed. This difference in nanocrystal size and density on different dielectrics is attributed to the different surface properties of these materials. © 2011 Materials Research Society.