The aims of this study were to determine the prevalence, size, shape, and location of torus palatinus (TP) and torus mandibularis (TM), and to investigate their sex-and age-related differences in a Thai population. One thousand two hundred subjects were examined for the presence of both tori at the Faculty of Dentistry, Chulalongkorn University. The prevalence for TP and TM in the subjects was 58.1% and 31.9%, respectively. TP were significantly more common in females than in males (67.3% versus 48.8%; p<0.001). TP were frequently found in small and medium sizes, spindle-shaped and often located at the combined premolar to molar and molar areas. The prevalence of TM was higher in males than in females (34.8% versus 29.0%; p=0.030). TM occurred most commonly in small size, bilateral multiple form, and was often located at the canine to premolar area. There was a significant correlation between the prevalence of both tori and age (p<0.001 for TP and p=0.004 for TM). The prevalence of both tori in this Thai population were comparable to the Mongoloids and other Asian populations. Statistically significant differences in the prevalence and size of tori in regard to sex and age were also found.