The article reviews the latest clinical and epidemiological evidence on gender and sex differences in the outcomes of COVID-19 in Europe and China. It highlights that while the number of cases between the sexes is similar, older men have more severe outcomes and higher case fatality rates, particularly those with pre-existing cardiovascular conditions. The review discusses potential sex-specific mechanisms, such as hormone-regulated expression of genes encoding for SARS-CoV2 entry receptors (ACE2 and TMPRSS2) and sex hormone-driven immune responses. It also explores the impact of gender-specific lifestyle, health behaviors, psychological stress, and socioeconomic conditions on COVID-19 outcomes. The authors emphasize the need to understand the impact of sex and gender on incidence and case fatality and to tailor treatments accordingly. They call for the inclusion of sex- and gender-sensitive analyses in ongoing and planned prophylactic and therapeutic treatment studies.The article reviews the latest clinical and epidemiological evidence on gender and sex differences in the outcomes of COVID-19 in Europe and China. It highlights that while the number of cases between the sexes is similar, older men have more severe outcomes and higher case fatality rates, particularly those with pre-existing cardiovascular conditions. The review discusses potential sex-specific mechanisms, such as hormone-regulated expression of genes encoding for SARS-CoV2 entry receptors (ACE2 and TMPRSS2) and sex hormone-driven immune responses. It also explores the impact of gender-specific lifestyle, health behaviors, psychological stress, and socioeconomic conditions on COVID-19 outcomes. The authors emphasize the need to understand the impact of sex and gender on incidence and case fatality and to tailor treatments accordingly. They call for the inclusion of sex- and gender-sensitive analyses in ongoing and planned prophylactic and therapeutic treatment studies.