BackgroundIn late December 2019, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) was identified as the cause of a series of pneumonia cases in China. Levamisole can show clinical benefits in management of COVID-19 by its immunomodulatory effect, but effect in clinical status of patients is unknown. We evaluated the efficacy of levamisole on clinical status of patients with COVID-19 on days 3, 7, and 14.MethodsThis prospective, double-blind, randomized, and controlled clinical trial was performed in 18- to 60-year-old patients with confirmed COVID-19 from late April 2020 to mid-August 2020. Patients were randomly assigned to two groups to receive a 5-day course of levamisole or placebo in combination with routine care. Results50 patients with COVID-19 were analyzed: 25 patients were in each group. More than half of the infected patients was men too (60%). On days 3 and 14, patients in Levamisole group had significantly better cough status distribution compared with Placebo (P=0.034 and 0.005, respectively). The difference in fever status on days 1, 3, 7, and 14 between two groups was not statistically significant (P > 0.05). There was significant differences between two groups in dyspnea over a median follow-up of 7th (P=0.015) and 14th (P=0.010) days after receiving the interventions. ConclusionThe results of the current study have overall demonstrated that patients receiving levamisole had significantly higher odds of having a better clinical status including cough and Dyspnea on day 14 than those receiving placebo, but with an effect-size of unsure clinical importance. The difference in the distribution of fever on days 3, 7, and 14 between two groups was not significant, suggesting that levamisole can efficiently improve the most clinical status of patients with COVID-19 infectious compared to placebo.Trial registrationThe trial was registered as IRCT20190810044500N7 (19/09/2020).