Patients lacking humoral response have been suggested to develop a less severe COVID-19, but there are some reports with a prolonged, relapsing or deadly course . From April 2020, there is growing evidence on the benefits of COVID-19 convalescent plasma (CCP) for patients with humoral immunodeficiency. Most of them had a congenital primary immunodeficiency or were on treatment with anti CD20 antibodies . We report on three patients treated in our hospital and review thirty-one more cases described in the literature . All patients but three resolved clinical picture with CCP . A dose from 200 to 800 ml was enough in most cases . Antibody levels after transfusion were negative or low, suggesting consumption of them in SARS-CoV-2 neutralization . These patients have a protracted clinical course shortened after CCP . CCP could be helpful for patients with humoral immunodeficiency. It avoid relapses and chronification . CCP should be transfused as early as possible in patients with COVID-19 and humoral immunodeficiency.