The outbreak of Coronavirus disease 2019 (COVID-19) has caused a global health crisis . Nevertheless, no antiviral treatment has yet been proven effective for treating COVID-19 and symptomatic supportive cares have been the most common treatment . Therefore, the present study was designed to evaluate the effects of propolis and Hyoscyamus niger L. extract in patients with COVID-19 . This randomized clinical trial was conducted on 50 cases referred to Akhavan and Sepehri Clinics, Kashan university of medical sciences, Iran . Subjects were divided into two groups (intervention and placebo). This syrup (containing 1.6 mg of methanolic extract along with 450 mg of propolis per 10 mL) was administered three times a day to each patient for 6 days . The clinical symptoms of COVID-19 such as: dry cough, shortness of breath, sore throat, chest pain, fever, dizziness, headache, abdominal pain, and diarrhea were reduced with propolis plus Hyoscyamus niger L. extract than the placebo group . However, the administration of syrup was not effective in the control of nausea and vomiting . In conclusion, syrup containing propolis and Hyoscyamus niger L. extract had beneficial effects in ameliorating the signs and symptoms of COVID-19 disease, in comparison with placebo groups.