Background A novel multisystem inflammatory syndrome in children (MIS-C) temporally associated with the coronavirus disease 2019 (COVID-19) infection has been reported, arising weeks after the peak incidence of COVID-19 infection in adults. Patients with MIS-C have been reported to have cardiac involvement and clinical features overlapping with other acute inflammatory syndromes such as Kawasaki-Disease, toxic shock syndrome, and macrophage activation syndrome. MIS-C may follow Covid-19 infection, most of the time after its asymptomatic form, even though it can lead to serious and life-threatening illness. Case summary In this case series, we discuss two cases of young adults with no former medical history who fit with the criteria defined in MIS-C. They both developed a refractory cardiogenic shock and required intensive care treatment including mechanical circulatory support, specifically the use of venous-arterial extracorporeal membrane oxygenation (VA-ECMO). They were both treated early with intravenous immune globulin and adjunctive high-dose steroids. They recovered ad integrum in less than two weeks. Discussion MIS-C occurs 2 to 4 weeks after infection with SARS-CoV-2. Patients with MIS-C should ideally be managed in an intensive care environment since rapid clinical deterioration may occur. It would be preferable to have a multi-disciplinary care to improve outcomes. Patients should be monitored for shock. Elucidating the mechanism of this new entity may have importance for understanding COVID-19 far beyond the patients who have had MIS-C to date. The pathogenesis seems to involve post-infectious immune dysregulation so early administration intravenous immune globulin associated to corticosteroids appears appropriate. It implies early recognition of the syndrome even in young adults.