Individually administered intelligence tests are a routine component of psychological assessments of children who may meet criteria for Attention-Deficit/Hyperactivity Disorder (ADHD), learning disorders (LD), or emotional and behavioral disorders (EBD). In addition to providing potentially useful test scores, the individual administration of an intelligence test provides an ideal opportunity for observing a child’s behavior in a standardized setting, which may contribute clinically meaningful information to the assessment process. However, little is known about the associations between test scores and test session behavior of children with these disorders. This study examined patterns of test scores and test session observations in groups of children with ADHD, LD, EBD who were administered the Stanford Binet Intelligence Scales, Fifth Edition (SB5), as well as in control children from the SB5 standardization sample. Three hundred and twelve children receiving special education services for ADHD (n = 50), LD (n = 234), EBD (n = 28) and 100 children selected from the SB5 standardization sample were selected from a data set of children who were administered both the SB5 and the Test Observation Form (TOF; a standardized rating form for assessing behavior during cognitive or achievement testing of children). The groups were then compared on SB scores and TOF scores. Associations between test scores and TOF scores in children with ADHD, LD, and EBD and normal controls were also examined. The results of this investigation indicated that children with ADHD, LD, and EBD and normal control children differed on several SB5 and TOF scales. Control children scored higher on all of the SB5 scales than children with LD, and scored higher on many of the SB5 scales than children with ADHD and EBD. Children with EBD demonstrated the most problem behavior during testing, followed by children with ADHD. Children with LD were similar to control children with respect to test session behavior. In addition, several combinations of test scores and test session behavior were able to predict diagnostic group status. Overall, the results of this investigation suggest that test scores and behavioral observations during testing can and should be important components of multi-informant, multi-method assessment of children with ADHD, LD, and EBD.