Ascariasis is a common soil-transmitted helminth infestation worldwide. Ascaris lumbricoides infestation is generally asymptomatic or cause nonspecific signs and symptoms. We report a 5-year-old male with hemophagocytic lymphohistiocytosis associated with A. lumbricoides infestation. The presented patient recovered completely after defecating an A. lumbricoides following intravenous immunoglobulin (IVIG) and mebendazole treatment. We wanted to emphasize that because helminth infestation is easily overlooked, the diagnosis of ascariasis should be considered in patients who live in endemic areas and treated timely to prevent severe complications.