Neonatal screening for cystic fibrosis (CF) has become feasible through analyzing dried blood specimens for immunoreactive trypsinogen (IRT), but the benefits and risks of such a screening program remain to be delineated. This study, a survey of the parents of 104 Wisconsin infants with false-positive IRT tests, showed parents had knowledge deficits about neonatal screening in general, misconceptions about test results, and high levels of anxiety. Parenting behaviors were reportedly unchanged during the usual 3-day waiting period between the news of the abnormal screening test and the diagnostic sweat test. Most, but not all, parents were relieved by negative sweat test results subsequent to the abnormal IRT test. Factors associated with continued parental concern included having less than a high school education and/or having an infant with low Apgar scores. Additionally, those contacted by telephone were more likely to have misinformation and lingering concerns about the presence of CF in their child.