Objectives: This study was designed to assess Health Care Professionals' knowledge about occupational therapy in Makkah-Saudi Arabia. Methods: Convenience sampling was used and 320 of Health Care Professionals, including physicians, nurses, physical therapists and social workers, were recruited from three different hospitals in Makkah to fill in a developed questionnaire. Descriptive analysis was used for participant's demographic data presentation. The mean percent scores were compared among four groups of professionals by using One-way ANOVA test with post hoc Tucky's Test. The comparison was done by using Chi-square test. Results: The study found that Health Care Professionals had poor knowledge about occupational therapy (49.35%, SD=7.36). It also exhibited that the highest percentage of knowledge about occupational therapy within the four groups was in physicians (51.97%) followed by physical therapists (50.81%, n=24) and nurses (48.32, n= 165), whereas social workers had the lowest percentage of knowledge (47.17%, n= 30). Conclusion: Health care professionals in Makkah lack adequate knowledge about occupational therapy, its goals and treatment methods. This dearth of knowledge among Health Care Professional requires to be addressed in order to improve the provision of service for patients in need of occupational therapy to subsequently improve their quality of life.