Objective-To assess parental health literacy and numeracy skills in understanding instructions for caring for young children, and to develop and validate a new parental health literacy scale, the Parental Health Literacy Activities Test (PHLAT).Methods-Caregivers of infants (age <13 months) were recruited in a cross-sectional study at pediatric clinics at three academic medical centers. Literacy and numeracy skills were assessed with previously validated instruments. Parental health literacy was assessed with the new 20-item PHLAT. Psychometric analyses were performed to assess item characteristics and to generate a shortened, 10-item version (PHLAT-10).Results-182 caregivers were recruited. While 99% had adequate literacy skills, only 17% had >9 th -grade numeracy skills. Mean score on the PHLAT was 68% (SD 18); for example, only 47% of caregivers could correctly describe how to mix infant formula from concentrate, and only 69% could interpret a digital thermometer to determine if an infant had a fever. Higher performance on the PHLAT was significantly correlated (p<0.001) with education, literacy skill, and numeracy level (r=0.29, 0.38, and 0.55 respectively). Caregivers with higher PHLAT scores were also more likely to interpret age recommendations for cold medications correctly (OR 1.6, 95% CI 1.02, 2.6). Internal reliability on the PHLAT was good (KR-20=0.76). The PHLAT-10 also demonstrated good validity and reliability. Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Conclusions-Many parents do not understand common health information required to care for their infants. The PHLAT, and PHLAT-10 have good reliability and validity and may be useful tools for identifying parents who need better communication of health-related instructions. NIH Public Access