Background: the joint replacement surgery is a great advance in the orthopedic medicine with a longlife promise of knee or hip reconstructive surgery which may exceeds 20 years old. Objectives: this study aimed to evaluate the knowledge of community Saudi adults regarding the joint replacement surgery in Jeddah City, Saudi Arabia (KSA), 2017. Methods: this was across sectional community based survey and it was conducted from May to August 2017 in Jeddah city among 670 adult Saudi subjects who were interviewed at shopping malls and community pharmacies. All the respondents answered a self-administrated questionnaire that considered the knowledge of respondents toward joint replacement therapy. Results: all the subjects heard before the term joint replacement therapy and the major source of information was from friends and relatives. Only nine subjects (1.3%) have undergone hip or knee replacement surgery. The level of awareness about joint replacement surgery was adequate in only 30.9% of subjects and insufficient among 69.1% of subjects. The higher level of awareness was significantly associated with old age. Conclusion: the level of awareness was inadequate among most of Saudi participants about the causes and effects of the joint replacement surgery. There is urgent need for public education about the joint replacement surgery to address the concerns and advantages of the surgery through media, internet and health educational campaigns.