Objective. This study compared the Missouri State Department of Health linked birth-infant death certificate database and medical records with respect to recording hyaline membrane disease in very low-birth-weight infants. Methods. We reviewed the records for all 976 infants weighing 500 to 1500 g who were born to St. Louis, Mo, residents in 1989, 1991, and 1992. Results. Eighteen percent of the birth certificates and 54% of the medical records documented hyaline membrane disease, resulting in 34% sensitivity and 99% specificity. Conclusions. The Missouri State Department of Health birth- infant death certificate database underestimates the incidence of hyaline membrane disease, which suggests that national statistics for the disease are also underestimated.