Selective mutism is a childhood disorder that most school psychologists and educational providers will come across at least once in their careers. Selective mutism is associated with significant impairment in educational settings where speaking is necessary for academic and social skill development. Effective treatments for selective mutism typically involve shaping or stimulus fading procedures. Choosing an effective treatment strategy for a child with selective mutism is dependent upon careful analysis of data gathered during the assessment process. This article focuses on behavior observations as a primary source of data for effective decision making regarding treatment for selective mutism. Previous literature on behavior observation and selective mutism is reviewed and guidelines are presented for decision making based on observational data. This article presents two case studies that illustrate the use of observational data for treatment decision making. In addition, the role of behavioral observations to inform selective mutism treatment decisions in practice and the need for future research on this topic are discussed.