Since the ongoing pandemic of COVID-19, caused by SARS-CoV-2, has had a signifi cant impact on public health and, also the clinical benefi ts of the medications are so limited, preventive measures may be able to help control its spread. Because the petroleum jelly compound could alter the physicochemical properties that affect adhesion, we investigated the preventive role of Petroleum jelly on covid-19 infection. Forty people with no sign and no history of covid-19 infection, were included in this study. They use petroleum jelly (Vaseline) nasally twice a day for about two months. After that time, participants tested by RT-qPCR to determine any infection with SARS-CoV-2 virus. There was a signifi cant difference in terms of RT-qPCR results between the intervention and control groups. Petroleum jelly may be effective in preventing covid-19 infection (Tab. 2, Fig. 1, Ref. 13).