Hemophagocytosis syndromes are uncommon disorders marked by generalized proliferation of benign histiocytes and multiple organ failure. A 24-year-old woman presented with a fulminant illness consisting of fever, hepatic insufficiency and anemia, followed by respiratory compromise, cardiomyopathy, and uremia. She developed a sensorimotor polyneuropathy, with normal cerebrospinal fluid findings. Sural nerve biopsy demonstrated mild to moderate axonopathy, with regeneration and occasional segmental demyelination/remyelination. The recent and old hemorrhages present in the perineurium, and the marked infiltration by foamy histiocytes (macrophages) distributed mostly in the subperineural space, were presumably responsible for the Wallerian degeneration. Documentation of histiocytes in peripheral nerves in hemophagocytosis syndrome has not previously been shown.