The objectives of this study were to investigate the relationship between the occurrence of torus palatinus with palatal arch dimensions and maxillary arch forms in Thai subjects. The study included 366 Thais with equal number of men and women. Subjects who had no torus palatinus showed significantly deeper palates than subjects who had torus palatinus (p<0.001). The palatal arch length and width did not differ in both groups. There were no association between the size of torus palatinus and palatal arch dimensions. Torus palatini were found more common on the maxillary arches with parallel (75.9%) and divergent ends (75.1%) than those with convergent ends (63.3%). However, these differences were not statistically significant. Our finding supported the previous study in that an association between the occurrence of torus palatinus and palatal arch height existed, but the relationship between the occurrence of torus palatinus and maxillary arch forms was not demonstrated.The objectives of this study were to investigate the relationship between the occurrence of torus palatinus with palatal arch dimensions and maxillary arch forms in Thai subjects. The study included 366 Thais with equal number of men and women. Subjects who had no torus palatinus showed significantly deeper palates than subjects who had torus palatinus (p<0.001). The palatal arch length and width did not differ in both groups. There were no association between the size of torus palatinus and palatal arch dimensions. Torus palatini were found more common on the maxillary arches with parallel (75.9%) and divergent ends (75.1%) than those with convergent ends (63.3%). However, these differences were not statistically significant. Our finding supported the previous study in that an association between the occurrence of torus palatinus and palatal arch height existed, but the relationship between the occurrence of torus palatinus and maxillary arch forms was not demonstrated.