Head start (HS) programs are required to collect children’s height and weight data. Programs also communicate these results to families. However, no standardized protocol exists to guide measurements or communicate results. The purpose of this article was to describe the development of a measurement toolkit and best practices for communication. HS programs contributed to the development and pilot testing of a toolkit for HS staff to guide child measurement. We used a three-phase iterative approach and qualitative methods to develop and test the toolkit, which included a video and handout. In addition, we convened an advisory group to draft best practices for communication. HS program staff appreciated the toolkit materials for their simplicity and content. The advisory group highlighted the importance of weight stigma and the need to be cautious in the way that information is communicated to families. The group underscored the role of emphasizing health behavior change, instead of focusing solely on BMI. Best practices were organized into (1) Policies and procedures for communicating screening results, (2) training for HS program staff to improve communication related to screening and health behaviors, and (3) other best practices to promote health behaviors and coordinate data systems. Our toolkit can improve anthropometric measurements of HS to ensure that potential surveillance data are accurate. Advisory group best practices highlight opportunities for HS to develop and implement policies, procedures, and trainings across the country to improve communication with HS families. Future research should test the implementation of these best practices within HS.