Educational administration is a rich domain of scholarship and practice, but one subject rarely discussed is its dark side. This study explored the question: What types of maladministration occur in schooling systems? The goal was to develop findings to inform existing prevention strategies. Focused on the Canadian context, data sources included 64 reports from disciplinary hearings of administrators in the Provinces of Ontario and British Columbia, complemented with other publicly available sources such as news stories. Findings indicated only a small minority of populations of administrators were subjected to disciplinary investigations and sanctions, but the targeted misconduct was often severe. Analysis revealed eight dimensions of maladministration, with sexual misconduct against students and financial transgressions being the most frequent. Academic dishonesty in the context of standardized testing and gendered patterns of maladministration also stood out. A typology emerged that highlighted the main forms of misconduct and negative leader behaviours against which schooling communities should bolster defences. When populated with data on the frequencies of acts of maladministration, the typology can help schooling communities to establish prevention priorities. The data in this study supports making the issues of sexual misconduct and the duty to report sexual abuse central to any planned interventions in the leadership system.