This study reviews recent research related to the neurobiology of Autism Spectrum Disorders (ASDs) an provides an empirical analysis of current assessment practices. Data were collected through a survey of 117 school psychologists. The Childhood Autism Rating Scale (CARS), Gilliam Autism Rating Scale (GARS), and Gilliam Asperger's Disorder Scale (GADS) were the most frequently used measures. Among the less popular, but more intensive instruments, the Autism Diagnostic Observation Schedule (ADOS) appears to be gaining popularity within school-based evaluations. Generally, respondents approached the assessment of ASDs from a traditional psychoeducational perspective and reported the use of a very narrow range of ASD-specific instruments. Concerns are raised regarding the inconsistent inclusion of developmental questionnaires, parent/guardian interviews, and medical professionals in the ASD evaluation process. Implications for practice and the training of school psychologists are discussed. © 2008 Wiley Periodicals, Inc.