Background: Respiratory tract infections are among the most frequently encountered clinical conditions and upper respiratory tract infections (URTIs) are one of the most common reasons for consultations in primary health care centres. Antibiotics are often prescribed unnecessarily for URTIs around the globe. Identifying factors associated with the ubiquitous inappropriate prescribing of antibiotics for URTIs will help develop effective interventions and decrease antimicrobial resistance. The Aim of the study was to find out the resources of physicians’ knowledge regarding upper respiratory tract infection management, and to identify the clinical factors that might affect antibiotics prescription by primary health care physicians. Methodology: This is cross sectional observational quantitative study was carried out at Primary health care centres during the period from January to August 2021 in Cluster-1 Riyadh, Saudi Arabia. An online self-administered questionnaire was conducted on 197 physicians by using convenient sampling technique. The data was analysed using SPSS software version 23. The study was done on all physicians who have worked in primary health care in cluster 1 for one year or more, male and female, Saudi and non-Saudi, and including consultants, specialists, residents and general practitioners. Results: In this study, we were able to collect 197 responses of our questionnaire with mean age of 31.6 years old (SD= 6.27). More than half of the participants were males (54.8 %) and 72.6 % of them were residents. Furthermore, 91.9 % of the participants reported following of criteria or guidelines for prescribing of antibiotics in treatment of UTRI. Among those physicians, 88.4 % of them reported depending on centor criteria. Furthermore, 70.6 % of the physicians reported a frequency of patient requests for antibiotic 1-4 times during the past months and 44.7 % of them would not accept the patients request while 28.9 % would refuse and educate the patients and 21.3 % would agree according to guidelines. Conclusion: We found good to moderate level of knowledge among the physicians toward the use of antibiotics in treatment of URTI however, some improvement in the patient’s knowledge should be considered. Keywords: antibiotics, URTI, primary healthcare, Saudi Arabia