Introduction: The COVID-19 pandemic has resulted in a global health crisis. SARS-CoV-2 infection and its broad spectrum of systemic involvement have demonstrated the existence of equally serious extrapulmonary complications in adult patients. In this context, Multisystem Inflammatory Syndrome (MIS), a serious complication that occurs after acute infection and has a hyperinflammatory nature with potential multisystem involvement, began to be reported as it developed in pediatric patients and in young and middle-aged adults. Experience report: Man, 36 years old, without previous comorbidities, with a history of COVID-19 infection, 4 months ago, with mild evolution and spontaneous resolution, seeks care for persistent fever for 20 days, generalized malaise, jaundice, choluria, chest pain and neck edema. Exams showed leukocytosis, with left shift, elevated PCR, negative blood culture. The tomography revealed an expansive lesion in the chest and cervical lymph node enlargement. The patient was admitted and underwent an exploratory cervicotomy for drainage and debridement, with prescription of intravenous antibiotics. Discussion: Multisystem Inflammatory Syndrome (MIS) associated with COVID-19 is a hyperinflammatory phenomenon that can cause organ dysfunction. Corticosteroids have been shown to be effective in treatment, but early diagnosis is crucial for a good prognosis. Conclusion: Adult Multisystem Inflammatory Syndrome (MIS-A) is a post-COVID-19 complication that can occur weeks after the initial infection. In this patient's case, multidisciplinary treatment, including surgery and various drug therapies, resulted in recovery. The case emphasizes the importance of raising awareness about MIS-A among health professionals and the need for research to improve diagnoses and treatments, as well as the importance of early interventions to manage the condition.