Pediatric Inflammatory Multisystem Syndrome (PIMS), or Multisystem Inflammatory Syndrome in Children (MIS-C), is a severe systemic inflammatory condition in children often occurring after asymptomatic SARS-CoV-2 infection. It is life-threatening, characterized by high fever (>38.5°C), and multisystem inflammation. Symptoms include severe abdominal pain, chest pain, arrhythmias, rash, and conjunctivitis. Laboratory findings typically show elevated inflammatory markers, coagulation abnormalities, and cardiac damage. Treatment involves immunoglobulins, glucocorticoids, and biological medicines to suppress immune hyperactivity, reducing inflammation and protecting organ function. PIMS/MIS-C has gained attention in the post-COVID-19 era, with an incidence of 2-5 cases per 100,000 children globally and 4 per 100,000 in Poland. Early recognition is crucial to mitigate severe outcomes. The report discusses a 6-year-old male presenting with high fever, abdominal pain, and rash, alongside laboratory evidence of inflammation and coagulopathy. Differential diagnoses included Kawasaki disease, septic shock, and toxic shock syndrome. Treatment followed the WHO guidelines, including immunoglobulins, glucocorticoids, and acetylsalicylic acid. Timely intervention prevented complications such as coronary aneurysms and myocardial dysfunction. Continued research and education are essential to enhance diagnostic and therapeutic strategies.