This study examined the perceptions of male and female administrators and special education teachers in Saudi Arabia regarding the use of Functional Behavior Assessment (FBA) in relation to its effectiveness and practicality for students with mental retardation. A four-part survey was developed by the researcher, focusing on administrators' and special education teachers': (1a) demographic information; and (1b) level of knowledge about functional behavior assessment; (2) perceptions regarding the practicality of using FBA; (3) perceptions regarding the advantages and disadvantages of using FBA sample of 394 administrators and special education teachers participated in this study. In addition, focus groups consisting of a total of 24 members participated. The major findings were: (1) the overall perceptions of Saudi administrators and special education teachers regarding the use of FBA in terms of its effectiveness, and its practicality were highly positive. (2) Female administrators and special education teachers had more positive perceptions of its effectiveness and it practicality than administrators and special education teachers.