Lay Summary Researchers have become interested in studying how health promotion activities fit within the organizational setting where they are delivered. Health activities that are integrated into the host setting's structures and routine operations are more likely to be fully executed, effective, and sustained. Unfortunately, we know little about how to achieve such integration. This is especially true when working outside of a healthcare system, in community organizations like churches. We report findings from a study that compared an approach to tailoring health promotion activities into their host settings, with a standard, non-tailored approach. The study was conducted in 14 African American churches randomly assigned to the tailored or standard group. The health promotion activity involved training lay people to conduct cancer educational workshops for church members. We measured the extent to which the churches integrated health promotion activities into their structures, processes, resources, and communication at the beginning and one year later. We found that while the churches had overall increases in these factors over time, those in the tailored group did not do so to a greater degree than those in the standard group. Even so, this approach to tailoring health promotion activities to the organizational setting merits future study. The field of implementation science has devoted increasing attention to optimizing the fit of evidence-based interventions to the organizational settings in which they are delivered. Institutionalization of health promotion into routine organizational operations is one way to achieve this. However, less is known about how to maximize fit and achieve institutionalization, particularly in settings outside of the healthcare system. This paper reports on findings from a parallel cluster-randomized trial that compared an organizationally tailored with a standard (core components only) approach for institutionalizing (integrating) an evidence-based cancer control intervention into African American churches. Churches randomized to the organizationally tailored condition identified three or more implementation strategies from a menu of 20, with an implementation time frame for each. The primary study outcome was assessed through the Faith-Based Organization Health Integration Inventory, a measure of institutionalization of health promotion activities in church settings, completed by pastors at baseline and 12-month follow-up. Seventeen churches were randomized and 14 were analyzed as 3 did not implement the study protocol. Though the percent increase in total integration score was greater in the tailored condition (N = 9; 18%) than in the standard condition (N = 5; 12%), linear mixed-effect models did not detect a statistically significant group x time interaction. Despite the challenges of integrating health promotion activities outside of healthcare organizations, the current approach shows promise for fostering sustainable health promotion in community settings and merits further study.