We conducted a retrospective cohort study of hospitalized patients at COVID-19 treatment Centres in Zambia from August 2020 to January 2021. Patients had demographic and clinical characteristics abstracted from their medical records. Severe COVID-19 was defined as: oxygen saturation 30 breaths/minute, or needing oxygen therapy at admission. Characteristics of participants by COVID-19 severity status were compared using a 2-sided Pearson chi-square test and Wilcoxon rank sum tests to assess for statistical significance Logistic regression was used to calculate the odds of severe COVID-19 adjusting for sex, treatment Centre, smoking and comorbidities