INTRODUCTIONThis study aims to analyze the differences in the prognosis and cost of COVID-19 patients in terms of mortality and occurrence of complications due to tobacco use.METHODSThis study was conducted using a unique Spanish electronic database built by health professionals during the first wave of the pandemic on the admission and evolution of a patient infected by the SARS-CoV-2 virus. Data were collected on all patients admitted to La Paz hospital (Madrid) from the pandemic’s beginning until 15 July 2020. Demographic factors and the incidence of complications in smoker and non-smoker patients were compared using the Mann-Whitney U-test or chi-squared test. Survival analysis was performed using the Kaplan-Meier estimator and Cox regression. Finally, the costs between the two groups were estimated using a Generalized Linear Model.RESULTSA total of 3521 patients were included in the analysis, with median age of 62 years (IQR: 47–78), 51.09% were women, and 16.42% were smokers. Patients who smoked had a higher incidence of complications during their hospital stay, especially complications related to the respiratory and cardiac systems. They were also associated with a worse prognosis in terms of the need for ICU admission and mortality, leading to an increase in the management cost of the smoking COVID-19 patients by 14.72%.CONCLUSIONSHealthcare in Spain is mainly financed by the national tax system, so introducing an additional financing system for pathologies related to the consumption of addictive substances and associated diseases and complications would decrease the burden on the economy in terms of healthcare.