Hemophagocytic syndrome (HS) is a rare life-threatening condition due to uncontrolled macrophagic activation. Liver involvement is constant in HS, characterized by Küpffer cell hyperplasia with hemophagocytosis. Conversely, the specificity, frequency, and clinical significance of this histologic lesion remain poorly investigated. We aimed to evaluate the prevalence of this elementary lesion in liver biopsies (LB) to attempt to identify its clinical significance and to investigate its potential association with perforin expression deficiency. Küpffer cell hyperplasia with hemophagocytosis has been systematically searched for in consecutive LBs in a 6-year period. In positive cases, clinical, biological, and outcome characteristics have been retrospectively recorded. The ratio of perforin to CD3(+) lymphocytes was assessed on immunostained LB sections. This histologic lesion was detected in LB of 69 of 5194 patients (1.3%). It was not associated with hepatotropic viral infection, alcohol-related chronic liver disease, or autoimmune chronic liver disease. Although only 36% of patients with this histologic lesion had a complete HS (association of fever, splenomegaly, bicytopenia, hypertriglyceridemia, hyperferritinemia, and/or hypofibrinogenemia), almost all patients had similar underlying diseases (human immunodeficiency virus infection, malignant hemopathy, and autoimmune disease) and/or acute ongoing infections (tuberculosis, cytomegalovirus, and Epstein-Barr virus). A decrease of the perforin to CD3(+) lymphocytes ratio was specifically associated with this lesion. Küpffer cell hyperplasia with hemophagocytosis in LB is a rare finding; although it does not necessarily denote a complete HS, it is associated with the same underlying disease and/or infection, with a decrease in intrahepatic perforin-positive lymphocytes.