Abstract This study evaluated the methods of data collection of birth certificate information by five high-delivery hospitals in northern Texas. Research purposes were to identify sources and methods of birth certificate data collection and identify the most-reliable methods. This descriptive study involved interviews of each hospital's data collectors and review of 1999 Texas birth certificate data. Medical record clerks, whose training varied, but usually consisted of orientation by another medical record clerk, collected birth certificate data within 24 hours of birth. There was no standard method for training, nor was there a minimum level of education required. In four of the five hospitals studied, a birth certificate clerk collected most of the information with limited input from other medical sources. The information obtained on birth certificates therefore varied according to the collector and the priority placed upon the accuracy of information. Birth certificate data contain questionable reliability, which undermines data use in research, funding, and policy decisions.