In 2012, I worked with agencies serving the developmentally disabled to implement and evaluate a mental health promotion intervention. Responding to the problem of managing clients' mental illness mainly through crisis intervention, we hoped to improve practice by trying an alternative approach. Previous studies indicated the problem was also occurring on a national and international level and solutions were urgently needed. Our yearlong intervention involved monthly meetings with clients and teams of their staff and family members. We evaluated our intervention by analyzing interviews with clients and team members. By framing our project from a strengths-based worldview and an action research design, we were able to integrate practical wisdom, published literature, and critical reflection. This case study illustrates challenges and setbacks that can occur in busy practice settings where precarious funding and staff turnover are a reality. Research with vulnerable populations requires deliberate attention to ensuring consensual, respectful, and ethical participation. Ethical considerations must be magnified with populations such as the developmentally disabled and even more so when co-occurring mental illnesses are present. Communication with participants is critically important, and explanations of practical strategies that work are presented.