This systematic review evaluates the effectiveness of various treatments for severe acute respiratory syndrome (SARS), including ribavirin, corticosteroids, lopinavir/ritonavir (LPV/r), type I interferon (IFN), intravenous immunoglobulin (IVIG), and convalescent plasma. The study, conducted in response to a request from the World Health Organization (WHO), analyzed data from 54 SARS treatment studies, 15 in vitro studies, and three acute respiratory distress syndrome (ARDS) studies. The review aimed to determine whether these treatments reduced mortality or morbidity in SARS patients or inhibited SARS-CoV replication in vitro. In vitro studies showed that ribavirin, LPV/r, and type I IFN inhibited SARS-CoV replication in cell cultures. However, in clinical trials, the evidence was inconclusive for most treatments. For ribavirin, 20 out of 24 studies were inconclusive, and four showed possible harm, including haemolytic anaemia. For LPV/r, two studies were inconclusive due to possible bias in control group selection. Corticosteroids showed mixed results, with some studies suggesting possible harm, while others showed no clear benefit. Type I IFN showed antiviral effects in vitro but was inconclusive in clinical trials. IVIG and convalescent plasma also showed inconclusive results. The review concluded that there was insufficient evidence to determine whether any of the treatments were effective in SARS patients. Some treatments may have been harmful. The authors emphasized the need for well-designed clinical trials to assess the safety and efficacy of treatments for future outbreaks. The review highlights the limitations of the available data and the importance of standardized protocols for future research.This systematic review evaluates the effectiveness of various treatments for severe acute respiratory syndrome (SARS), including ribavirin, corticosteroids, lopinavir/ritonavir (LPV/r), type I interferon (IFN), intravenous immunoglobulin (IVIG), and convalescent plasma. The study, conducted in response to a request from the World Health Organization (WHO), analyzed data from 54 SARS treatment studies, 15 in vitro studies, and three acute respiratory distress syndrome (ARDS) studies. The review aimed to determine whether these treatments reduced mortality or morbidity in SARS patients or inhibited SARS-CoV replication in vitro. In vitro studies showed that ribavirin, LPV/r, and type I IFN inhibited SARS-CoV replication in cell cultures. However, in clinical trials, the evidence was inconclusive for most treatments. For ribavirin, 20 out of 24 studies were inconclusive, and four showed possible harm, including haemolytic anaemia. For LPV/r, two studies were inconclusive due to possible bias in control group selection. Corticosteroids showed mixed results, with some studies suggesting possible harm, while others showed no clear benefit. Type I IFN showed antiviral effects in vitro but was inconclusive in clinical trials. IVIG and convalescent plasma also showed inconclusive results. The review concluded that there was insufficient evidence to determine whether any of the treatments were effective in SARS patients. Some treatments may have been harmful. The authors emphasized the need for well-designed clinical trials to assess the safety and efficacy of treatments for future outbreaks. The review highlights the limitations of the available data and the importance of standardized protocols for future research.