This study was undertaken to evaluate the reliability of parental reporting of their children's immunization status. One hundred eight consecutively admitted children to Brookdale University Hospital and Medical Center were sampled during October and November 2001. Review of the immunization record, recording the immunizations documented, and matching it with the parents' report was done for children in whom the parents brought the cards. The primary care physician was contacted to verify the immunization status for children for whom the parents did not bring the card during hospitalization or for whom there was a mismatch between the card and the parents' report. The study included 100 patients (8 were excluded). Forty-nine patients had their immunization cards on admission; 18 brought the cards later during the hospital stay. Of the 100 parents questioned, 98 stated that their children are up to date and 2 stated that their children are missing vaccinations. Of the 98 parents who stated that their children are up to date, 2 were found not to be up to date. Ninety-eight percent of parents were aware of their children's immunization status and were accurate with their reporting. Parents are knowledgable of their children's immunization status (98% parental accuracy) and their statements can be relied on during history-taking. It is important for each child to have a primary care physician.