Teeth in casts of a random sample from the Hong Kong Oral Health Survey of 12-year-old children (n=459; 295 boys and 164 girls) were measured in the mesiodistal, buccolingual, and clinical crown height dimensions. Sexual dimorphism was evident in all tooth types in nearly all tooth dimensions, with the exception of the mesiodistal dimension of mandibular central incisors. The Chinese male tooth dimensions were larger than in females in nearly all characters. The measurements were compared with other human groups. Results showed that the Southern Chinese had larger tooth dimensions than the Japanese and than the White Americans. Hence it is important to have data concerning a relevant human group for purposes of clinical diagnosis and planning of treatment. These data may also be useful in forensic dentistry.