AbstractDental health education attempts to change behaviour by altering an individual's knowledge, attitudes, and belief's about health matters. Perception of vulnerability to illness and dental disease is a central, but poorly understood, health belief. In this study of 303 New Zealand and 297 Australian schoolchildren perceived vulnerability was measured by the degree of expectancy to which subjects believed they would contract health problems. The pattern of health problem expectancy was consistent across age groups, cultures, and other demographic divisions. High expectancies of general health problems and dental caries were associated with potential preventive dental visits and with potential denture wearing. New Zealand schoolchildren, and children from lower socioeconomic backgrounds, had higher expectancies of general health problems and dental caries than Australian or middle class children.