This systematic review examines the association between smoking and COVID-19 outcomes, including disease severity, need for mechanical ventilation, ICU hospitalization, and death. The review included five studies conducted in China, covering the first two months of the pandemic. The studies found that current and former smokers were more likely to have severe symptoms, require ICU admission, mechanical ventilation, or die compared to non-smokers. Specifically, smokers were 1.4 times more likely to have severe symptoms and 2.4 times more likely to require critical care or die. While the evidence is limited, the review suggests that smoking is likely associated with adverse outcomes in COVID-19 patients. Further research is needed to confirm these findings.This systematic review examines the association between smoking and COVID-19 outcomes, including disease severity, need for mechanical ventilation, ICU hospitalization, and death. The review included five studies conducted in China, covering the first two months of the pandemic. The studies found that current and former smokers were more likely to have severe symptoms, require ICU admission, mechanical ventilation, or die compared to non-smokers. Specifically, smokers were 1.4 times more likely to have severe symptoms and 2.4 times more likely to require critical care or die. While the evidence is limited, the review suggests that smoking is likely associated with adverse outcomes in COVID-19 patients. Further research is needed to confirm these findings.