Abstract The stability, formation energy, relaxation field, binding energy and strength dipole tensor of a number of vacancy and interstitial defect configurations in Mg(hcp) has been studied using the computer simulation technique. The split interstitial along the c-axis is found to be the most stable and not the tetrahedral configuration as implied by Tome et al who have not studied the dumb-bell. Amongst vacancy configurations two configurations each of di- and tri-vacancies have been found to be equally stable.