We investigated nanocrystalline nickel experimentally (x-ray diffraction) and theoretically (cluster ab initio calculations). No phase transition was observed in nano-nickel. The volume, isothermal bulk modulus and its pressure derivative derived experimentally and theoretically are 43.56 (0.13) Angstrom (3), 228(15) GPa, 4.02(0.51) and 44.00 Angstrom (3), 217 GPa and 3.20, respectively. We found no appreciable change in the value of bulk modulus for nano-nickel as compared to the bulk-nickel.