Introduction: The high rate of catastrophic health care expenditure is a challenging problem societies face today. Identifying the influential factors on the expenditure is an important measure which should be taken to control them. In this study, the catastrophic health expenditure and its influential factors were examined.

  Methods: Within the framework of Health Center Province, 400 households were
selected in winter 2011. The WHO’s health questionnaire was completed for them by the researchers. The incidence of catastrophic health expenditure was evaluated in accordance with the World Health Organization definition and influential factors on the expenditures were investigated by using Stata software 11.

  Results: It was found that 8.3 Present of the families of Yazd province were exposed to catastrophic health expenditure. The use of inpatient services was shown to have the largest amount in paid-out-of-pocket expenditure and their relationship to incidence of catastrophic health expenditure was found to be significant. It was, moreover, found that the relationships between family sizes, persons below 5 years old in the families, and the use of medical services and diagnosis with catastrophic health expenditure were significant.

  Conclusion: The variables of medicine, diagnosis, inpatient services and persons below 5 years old in household and family size should be seriously taken into account by policy makers to control Catastrophic Health Expenditure