Study aim: Determining the effect of ivermectin on RT-PCR test, clinical improvement, mortality and duration of hospitalization in patients admitted with COVID-19 Design: Clinical trial with control group, parallel groups, double-blind, randomized, phase 3 on 1000 patients. Patients will be divided into two groups by a simple randomization method with a table of random numbers. The control group will receive standard and placebo treatment and the intervention group will receive Ivermectin for three days in addition to the standard treatment. Settings and conduct: COVID-19 positive rapid test or RT-PCR patients admitted to Buali and Imam hospitals of Sari, Razi hospital of Qaemshahr, Imam Hossein hospital of Neka and Imam hospital of Fereidoonkenar will be divided into two groups of intervention and control. The present study will be double-blind so that patients and physicians will be unaware of how the intervention and control groups assigned. Participants/Inclusion and exclusion criteria: Inclusion criteria: Patients with COVID-19 positive rapid test or RT-PCR; aged >5 years; weight more than 15 kg and without liver and lung disease and acquired immunodeficiency and pregnancy lactation and without treatment with antiviral drugs before and during the study are included. Intervention groups: Intervention group: Iranian standard treatment protocol for COVID-19 in addition to 6mg Ivermectin tablet made by Alborz Daru Company of Iran for 3 days. Control group: In the control group, placebo tablets made by Alborz Daru Company of Iran with the same shape, color and weight based dose of ivermectin will be used for three days. Main outcome variables: Clinical improvement, Duration of hospital stay, Rate of Mortality