BACKGROUND: This case series aims to evaluate the presenting symptoms, laboratory data, systemic findings, and response to early treatment in patients who were followed up with the diagnosis of multisystemic inflammatory syndrome associated with novel coronavirus disease 2019 (COVID-19). METHODS: The presentation, laboratory findings, and responses to treatment of patients hospitalized and diagnosed with multisystemic inflammatory syndrome were evaluated retrospectively. RESULTS: A total of 32 patients were included in the study. The median age was 90 (1.5-204) months and 62.5% of the patients were male; 59.4% of the cases were non-specific disease, 31.2% typical (complete) Kawasaki, and 9.4% had phenotypic characteristics of atypical (incomplete) Kawasaki. Most of the patients were found to have low albumin and elevated C-reactive protein, sedimentation rate, and d-dimer, and all patients had elevated N-terminal pro-B-type natriuretic peptide, and procalcitonin. Lymphopenia was detected in 25 patients (78.1%) and serum ferritin levels were elevated in 25 patients (78.1%). Eleven (34.4%) patients responded well only to intravenous immunoglobulin treatment. Twenty patients (62.5%) received intravenous immunoglobulin and steroid therapy (second-line therapy). Only one patient (3.1%) received third-line therapy (intravenous immunoglobulin + steroid +anakinra + plasmapheresis). None of the patients died. CONCLUSIONS: Most patients had mild clinical symptoms and responded well to intravenous immunoglobulin and / or steroid therapies as first- and second-line therapies. Only one of our patients was clinically stabilized after third-line treatment because he did not respond to intravenous immunoglobulin and steroid therapy. We think that all of our patients diagnosed with multisystem inflammatory syndrome in children recovered because we had recommended quickly medical intervention. Treatment should therefore be started immediately in patients diagnosed with multisystem inflammatory syndrome in children. If there is no response after 24 h to the initial treatment, the next treatment protocol should be started.