The study aimed to evaluate possible role of oral ivermectin as a chemoprophylaxis in asymptomatic family close contacts with COVID-19 patients. A prospective interventional randomised open label-controlled study was conducted (registered at clinicaltrials.gov; NCT04422561) during June and July 2020. Two arms were designed according to use of ivermectin. In ivermectin arm, contacts received ivermectin according to Body Weight (BW) on day of the diagnosis of their index case. The nonintervention group received no treatment. The protection rate for ivermectin was more prominent in contacts aged less than 60-year-old (6.2% infected compared to 58.7% if no treatment). Ivermectin in the protection against SARS-CoV-2 infection had an OR of 12.533 and 11.445 (compared to nontreatment) in both univariate and multivariate models, respectively. Side effects of ivermectin were mild. Ivermectin is suggested to be a promising, effective and safe chemoprophylactic drug in