Background and Purpose: Medical emergencies in dental offices are unavoidable. Saving lives and sustaining health of patients against diseases and emergency situations is the most serious challenge in all medical treatment as well as dental treatment, therefore if dentists lack the adequate knowledge and don't know how to cope with such situations, the patient's life will be threatened. This study was carried out to determine dentists' knowledge and preparedness of medical emergencies in dental offices in Yasuj in 2016. Material and Method: This is a descriptive cross-sectional study. Research tool is a questionnaire with 4 parts. Data was gathered and encrypted then transmitted to SPSS software, version 15. Chi-square and Fisher tests were used. Statistical significance level was set at p< 0.05. Result: The highest measure of knowledge belonged to male specialists with mean and standard deviation of [7±1.7] and the least measure of knowledge belonged to female specialists with mean and standard deviation of [5.2±2.5]. Furthermore, female dentists’ knowledge of medical emergencies was more than males. There is a significant relation between number of available drugs in offices and gender. Conclusion: Overall, measure of knowledge of dentists in Yasuj City obtained 1.5 ±5.7 which is considered to be average. There is a significant relation between number of available drugs in offices and gender.