The clinical and laboratory features of hemophagocytic lymphohistiocytosis (HLH) are nonspecific that makes the definitive diagnosis of HLH very challenging. The disease is almost universally fatal in the absence of early recognition and appropriate therapy. Elevated serum ferritin level is one of the diagnostic markers of HLH disease. We report the value of testing serum ferritin level early in the disease process in 3 pediatric patients who presented with persistent fever and sepsis-like features. Detection of elevated serum ferritin levels facilitated further testing to confirm the diagnosis of HLH and initiate early therapy with good outcomes.