In anthropological studies based on frequencies of nonmetric traits, the choice between sampling by individuals or by sides remained by difficulty. Though the assumption about the biological meaning of asymmetry has been interpreted in various ways, little attention has focused on the meaning of bilateral nonmetric traits of Korean adult skulls. This study examined the asymmetric occurrence of nonmetric traits of Korean skulls and the correlations between these non metric traits. Eighteen traits were investigate in 161 Korean adult skulls and fifteen items were compared between right and left. Asymmetry was evaluated by paired-t test and correlation analysis was carried out. Most of nonmetric traits were tend to appear asymmetrically. Especially, the epipteric bone and the absence of mastoid foramen showed high affinity of asymmetry. In addition, the correlation coefficients among the nonmetric traits did not show any statistical significance. These results are consistent with the hypothsis that nonmetric traits were negatively related to symmetrical occurrence.