The hematologic values in patients with Haemophilus influenzae meningitis were contrasted with those of patients with other types of bacterial meningitis and aseptic meningitis in an attempt to determine whether anemia is either specific for or more common in patients with H influenzae meningitis. Patients with H influenzae meningitis had significantly lower admission hemoglobin values because they were significantly younger than the other two groups. The H influenzae meningitis patients with the lowest hemoglobin values on admission had been sicker for longer periods prior to diagnosis and had higher initial white cell counts. Patients with H influenzae meningitis, aged 3 to 24 months, developed lower hemoglobin values during hospitalization than did patients with other forms of meningitis. Anemia occurs with all forms of bacterial meningitis but is uncommon in aseptic meningitis. The anemia observed in patients with H influenzae meningitis, particularly those less than 2 years of age, is generally more severe than that observed in other forms of bacterial meningitis.