The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes Coronavirus Disease 2019 (COVID-19). This study aimed to characterize patients hospitalized with COVID-19 in Poland between March and December 2020, as well as to identify factors associated with COVID 19–related risk of in-hospital death. This retrospective analysis was based on data from the hospital discharge reports on COVID-19 patients hospitalized in Poland between March and December 2020. A total of 116,539 discharge reports on patients hospitalized with COVID-19 were analyzed. Among patients with COVID-19, 21,490 (18.4%) died during hospitalization. Patients over 60 years of age (OR = 7.74; 95%CI: 7.37–8.12; p < 0.001), men (OR = 1.42; 95%CI: 1.38–1.47; p < 0.001) as well as those with cardiovascular diseases (OR = 1.51; 95%CI: 1.46–1.56; p < 0.001) or disease of the genitourinary system (OR = 1.39; 95%CI: 1.31–1.47; p < 0.001) had much higher odds of COVID 19–related risk of in-hospital death. The presence of at least one comorbidity more than doubled the COVID 19–related risk of in-hospital death (OR = 2.23; 95%CI: 2.14–2.32; p < 0.01). The following predictors of admission to ICU were found in multivariable analysis: age over 60 years (OR: 2.03; 95%CI: 1.90–2.16), male sex (OR: 1.79; 95%CI: 1.69–1.89), presence of at least one cardiovascular disease (OR: 1.26; 95%CI: 1.19–1.34), presence of at least one endocrine, nutritional and metabolic disease (OR: 1.17; 95%CI: 1.07–1.28).