In April 2020, Pediatric Inflammatory Multisystem Syndrome temporally associated with severe acute respiratory syndrome coronavirus 2 or SARS‑CoV‑2 (PIMS-TS) was described for the first time in children. Since then, many countries have registered hundreds of cases with clinical similarities to Kawasaki disease. We report the case of a five-year-old boy diagnosed with PIMS-TS who presented myocarditis with serous effusions (pleurisy, ascites, pericarditis) due to severe hypoalbuminemia. This case sheds light on the importance of hypoalbuminemia in evaluating the severity of PIMS-TS and preventing its complications. The patient was successfully treated with intravenous immunoglobulins and oral prednisone.