Background: Asthma is one of the leading causes of school absenteeism. Schools can play an important role in coordinating asthma care. The purpose of this study was to assess the implementation of asthma-related school health policies and practices across states and how they have changed over time. Methods: Data were analyzed from 36 states that conducted School Health Profiles surveys during 2008 to 2018. Trends in 6 topics were analyzed by logistic regression and JointPoint trend test. Results: Trends in efforts to identify and track students with asthma and improve students' and parents' knowledge about asthma were stable or increased. Interest among lead health education teachers in receiving professional development on asthma trended downward in 35 of 36 states. Conclusions: Stable to upward trends suggest that a majority of schools have maintained or improved their efforts to identify and track students with asthma and increase the knowledge of students and parents about asthma. However, further improvement is needed in referral of students with asthma to health care professionals and encouraging asthma-related professional development of lead health education teachers.