OBJECTIVES: Here we aimed to estimate how well the excess mortality reflected the burden of COVID-19-related deaths and whether the excess mortality during the outbreak might have resulted in a compensatory reduced mortality after the March-May Covid-19 outbreak in Stockholm, Sweden. METHODS: Using previous 10-year or 5-year average mortalities as a baseline we compared the excess mortality estimates before, during and after the March-May 2020 outbreak in Stockholm. RESULTS: Weekly death estimates revealed that the immediate pre-outbreak and post-outbreak all-cause mortalities did not exceed to excess mortalities regardless of using previous 10-year or 5-year average mortalities. Forty-three days after the start of the outbreak, 74.4% of the total excess mortality was reportedly explained by known COVID-19-related deaths, and here we update that 15 weeks after the start of the outbreak the reported COVID-19-related deaths explained >99% of the total excess mortality. CONCLUSIONS: Exceptional outbreak feature of rapid excess mortality was observed. However, no excess but similarly low mortality was observed immediately prior to the outbreak and post-outbreak, and thus emphasizing the severity of the first wave of COVID-19 outbreak in Stockholm.