BACKGROUND AND OBJECTIVES: Corona Virus Disease 2019 (COVID-19) pandemic is a global health emergency. Health Care Workers (HCWs) with sound knowledge and practices can help curb the pandemic. This study aimed to assess the knowledge, attitude and practices of HCWs about COVID-19 and compare physicians and non-physicians in Saudi Arabia. METHODS: An online survey was conducted among HCWs in Saudi Arabia in March and April 2020. Data were collected using a structured questionnaire having four sections including; socio-demographic and professional profile, knowledge, attitude and practices regarding COVID-19. Questionnaire link was sent through social media. Descriptive analysis was used for assessment of knowledge, attitude and practice and Chi-square test was used for comparing physicians and non-physicians. Data were analyzed using SPSS version 21.0. RESULTS: A total of 398 HCWs completed the questionnaire. Only 45% of the participants had correct knowledge about the agent while about 97% knew that close contact with infected person is the most important risk factor. Only 63% had correct knowledge about the role of antibiotics in COVID-19 treatment. Majority of the HCWs were worried and most frequently reported worry was risk to family. Carrying infection to home was most commonly reported fear, 92%. Cleaning hands often or always was 11.5% and 87% respectively. About 71% wore mask during work. Knowledge was better among physicians compared to non-physicians while attitude and practices were comparable between the two groups. CONCLUSION: We found that there was poor knowledge about causative agent and role of antibiotics for COVID-19 but for mode of transmission and prevention there was good knowledge. There were widely prevalent worries and fears among the participants. Overall, there were good infection control practices among the HCWs. Interventions are needed to improve knowledge and address worries and fears of HCW.