The Federal Statistical Office publishes weekly national and regional mortality reports online for Switzerland for the age groups 0 to <65 and 65+ years, which refer to deaths up to 9 days prior to the publication date. In addition to observed numbers of death events, expected numbers are reported, which allows detection of periods of excess mortality and its quantification. As with previous periods of excess mortality, in 2020 the monitoring detected and quantified excess mortality during the two waves of the SARS-CoV-2 epidemic in Switzerland. During the year, the epidemic resulted in well over 10% more deaths than expected, mainly in individuals aged 65 years and above. Because of the profound impact of the epidemic, interest in the weekly mortality publication and its underlying methodology increased sharply. From inquiries and from newspaper and tabloid publications on the matter it became abundantly evident that the principles of the mortality monitoring were not well understood in general; mortality monitoring was even regularly confused with cause of death statistics. The present article therefore aims at elucidating the methodology of national mortality monitoring in Switzerland and at putting it into its public health context.