Background: This study examines the extent to which schools implement activities on health promotion and prevention during the COVID-19 pandemic. Moreover, potential differences with regard to demographic variables, school type, state, and participation in state health promotion initiatives are determined. Methods: As part of the international COVID Health Literacy Network, an online-based study was conducted from March to April 2021 with 2186 school principals from the German federal states of Baden-Württemberg, Hesse, Lower Saxony, and North Rhine-Westphalia. The implementation status of COVID-19-related school health promotion was assessed using a self-developed instrument. After examining the factorial structure of the instrument, univariate and bivariate data analyses were performed. Results: Three dimensions of implementing school health promotion can be identified: (1) COVID-19-related support for pupils, (2) health promoting design of teaching, learning, and working conditions, and (3) the principles of Health Promoting Schools. A low level of implementation is observed for aspects of teaching, learning, and working conditions as well as for participation and cooperation with community stakeholders. Significant differences are observed, with female, older, and primary school principals reporting a higher implementation status, while for federal states non-homogenous differences are found. Stratified by participation in state health promotion initiatives, only schools with a certificate in health promotion show a higher level of implementation. Discussion: The results indicate that the COVID-19 pandemic is a disruptive event for schools, impeding the implementation of holistic activities on health promotion and prevention. In particular, more attention should be given to the creation of health promoting working conditions, participation, and community cooperation.