The project aims were to (1) develop an observational Health and Safety Checklist to assess health and safety practices and conditions in early care and education (ECE) programs using Stepping Stones To Caring For Our Children, 3rd Edition national standards, (2) pilot test the Checklist, completed by nurse child care health consultants, to assess feasibility, ease of completion, objectivity, validity, and reliability, and (3) revise the Checklist based on the qualitative and quantitative results of the pilot study. Methods The observable national health and safety standards were identified and then rated by health, safety, and child care experts using a Delphi technique to validate the standards as essential to prevent harm and promote health. Then, child care health consultants recruited ECE centers and pilot tested the 124-item Checklist. The pilot study was conducted in Arizona, California and North Carolina. The psychometric properties of the Checklist were assessed. Results The 37 participating ECE centers had 2627 children from ethnically-diverse backgrounds and primarily low-income families. The child care health consultants found the Checklist easy to complete, objective, and useful for planning health and safety interventions. The Checklist had content and face validity, inter-rater reliability, internal consistency, and concurrent validity. Based on the child care health consultant feedback and psychometric properties of the Checklist, the Checklist was revised and rewritten at an 8th grade literacy level. Conclusion The Health and Safety Checklist provides a standardized instrument of observable, selected national standards to assess the quality of health and safety in ECE centers. (author abstract)