Purpose : This study was conducted to validate enzyme immunoassay (EIA) for the quantitative measurement of human IgG antibodies specific for Haemophilus influenzae type b (Hib) capsular polysaccharide. Method : We evaluated specificity, repeatability, intermediate precision, accuracy, lower limit of quantification (LLOQ), and stability to validate standardized EIA for the quantitative measurement of human anti-polyribosylribitol phosphate (PRP) IgG antibodies. Results : The results indicated that this EIA showed specificity to HbO-HA antigen and repeatability and intermediate precision were within acceptance criteria (repeatability: CV≤15%, intermediate precision: CV≤20%). The EIA-derived results from this laboratory were equivalent to those obtained by the standard radioactive antigen binding assay (RABA) for quantitation of anti-PRP antibodies in the 28 sera. Spiking recovery result was within acceptance criteria (100±20%). The precision and accuracy of samples in LLOQ were from -14.7 to -4.7% in nominal values, which were within acceptance criteria (precision: CV≤25%, accuracy: ±25%). Freeze-thaw stability and short term temperature stability were within ±20% of acceptance criteria. Conclusions : The EIA which is performed at the Center for Vaccine Evaluation and Study Ewha Medical Research Institute, is an appropriate serologic assay which can be used for quantitation of anti-PRP IgG antibodies in human sera.