Indian infant mortality rates (IMR) in the State of Oklahoma follow a downward linear trend from 13 per 1,000 live births in the 1975-76 period to 5.8 in 1987-88. Data from 7,631 death certificates matched to birth certificates, however, reveal much higher Indian IMR across the time interval than is currently documented. Matching (linking) of infant deaths to birth certificates from 1975 to 1988 indicates that infants born Indian had a 28 percent chance of being misclassified as another race (usually white) on the death certificate. Infants born white or black had less than a 1 percent chance of being misclassified. Misclassification of Indian deaths strongly alters the overall IMR for the Oklahoma Indian population from the currently reported 5.8 per 1,000 (1987-88) to an estimated actual rate of 10.4 per 1,000 for the same period.