BACKGROUND There is no evidence-based treatment for coronavirus disease 2019 (COVID-19). We report the case of a 63-year-old woman with SARS-CoV-2 infection who developed severe COVID-19 pneumonia and was treated with convalescent plasma. CASE REPORT A 63-year-old woman who presented with severe and prolonged course of COVID-19 disease (fever up to 39.4°C, persistent cough, and dyspnea) received a convalescent plasma transfusion, which led to complete recovery. The diagnosis was confirmed by RT-PCR testing using the CFX96 Real-Time System (Bio-Rad, USA) from nasopharyngeal swabs. In laboratory tests, an increase in acute-phase parameters was observed. Chest computed tomography (CT) showed abnormalities typical for COVID-19. On days 9 and 11 of the disease, she received the convalescent plasma prepared from a single plasmapheresis donation from a male donor. This male donor was qualified as a convalescent plasma donor according to Polish guidelines, which are compliant with European guidelines. He donated plasma at the Regional Centre for Transfusion Medicine in Białystok, Poland. The therapy with convalescent plasma led to clinical improvement and normalization of inflammatory parameters. CONCLUSIONS This report presents a case of severe COVID-19 pneumonia in a 63-year-old woman who was given supportive treatment with convalescent plasma. Ongoing clinical trials will determine whether convalescent plasma therapy is an effective treatment for SARS-CoV-2 infection.