Behavior rating scales are commonly used as part of the evaluation process throughout the field of psychology. Behavior rating scales help assess social, emotional, and/or behavioral problems in children, adolescents, and teens. Behavior rating scales indicate the severity of problem behaviors compared to a normative sample. Four scenarios were developed that varied scores on a behavior rating scale and the amount of other information that supported a specific diagnosis. A rating of the likelihood of a diagnosis was requested to see how much influence behavior rating scale scores have on diagnostic decision-making. Each of the four scenarios was sent to 200 school psychologists across the country for a total of 800 potential participants. An overall response rate of 37.5% was achieved. The findings revealed that behavior rating scales do have some influence on school psychologists’ diagnostic decision-making. However, school psychologists put more weight on other supporting information, such as classroom observations and teacher and parent reports, than on behavior rating scale scores when making a diagnostic decision.