Introduction: Systemic sarcoidosis is a rare multisystem rheumatologic disorder that is diagnosed after ruling out other granulomatous diseases. Clinical manifestations and treatment in these pediatric patients are also a challenge. Treatment is typically based on corticosteroids and cytotoxic agents; however, no organ‐specific treatment currently exists. Recent studies have demonstrated the effectiveness of anti‐TNF drugs in treating pulmonary and extrapulmonary sarcoidosis. Case Presentation: We report the case of a 16‐year‐old boy who, since the age of 12, presented with cytopenia, constitutional symptoms, and abdominal pain without a definitive diagnosis. At Age 16, he developed massive splenomegaly with lung and renal involvement. A diagnosis of systemic sarcoidosis was confirmed via a spleen biopsy. He was treated with infliximab in combination with corticosteroids and a cytotoxic agent. Conclusion: This report emphasizes the importance of diagnosing sarcoidosis based on rare and nonspecific signs and symptoms and treatment choices. Early diagnosis of this disease can lead to more effective treatment and prevent multiple organ involvement. Although there is not any organ‐specific treatment for systemic sarcoidosis in children, with just a few reports of effectiveness of infliximab in kidney involvement, we decided to treat our case with infliximab because of corticosteroid and cytotoxic failure. This treatment may show that infliximab plays a key role in treating corticosteroid‐resistant sarcoidosis that affects certain organs, like the kidneys, or in reducing the side effects of corticosteroid drugs.