Summary: Background: One of the effects of the coronavirus disease 2019 (COVID‐19) pandemic is the risk of shortages in Blood Centres.Objectives: To verify the impact of the COVID‐19 pandemic on the blood donor's attendance and production of blood components in Fundação Hemominas, a Brazilian public institution was formed by several Blood Centres.Methods: A cross‐sectional study was carried out from January to June 2020. Data collected were compared to a historical series from 2016 to 2019.Results: The study showed a reduction in the attendance of blood donors, whole blood collections and blood component production from March 2020, when the first case of COVID‐19 was notified in Minas Gerais, Brazil. The results evidenced that Hemominas Blood Centres were affected in a very distinct way by the pandemic with a general mean reduction around 17% in attendance of blood donors and in production of blood components in the period of March to June. On the other hand, the return of blood donors rate increased.Conclusion: The reduction in blood donation during the pandemic period was significant, despite the measures adopted. Still, the recruitment of return donors appears to be an important measure to be considered to decrease the pandemic's effect on blood stocks.