The use of individually administered measures of intelligence and other cognitive abilities requires clinicians to monitor a client's test behaviors, given the need for a client to be engaged fully, attentive, and cooperative during the testing process. The use of standardized and norm-referenced measures of test-taking behaviors facilitates this important clinician-centered evaluation process. Research on children's test-taking behaviors identifies Avoidance, Inattentiveness, and Uncooperative Mood as being counterproductive to performance on tests of cognitive abilities. Two prior studies examines the influence of these three test-taking behaviors on WISC (Wechsler Intelligence Scale for Children-IV, Spanish) full-scale IQs of Hispanic children and youth. The first, with English-speaking Hispanic children and youth, finds their test-taking behaviors to be low and to account for approximately 30% of the variance in their full-scale IQs. The second, with Hispanic children and youth who were acquiring English, finds their test-taking behaviors to be average and to account for approximately 9% of variance in their full-scale IQs on the WISC-IV Spanish. The current study extends this research by examining the impact of the above-mentioned test-taking behaviors on four domain scores (i.e., verbal comprehension, perceptual reasoning, working memory, and processing speed) obtained by Hispanic children and youth who constitute part of the standardization sample of WISC-IV Spanish. The GATSB (Guide to the Assessment of Test Session Behavior) total score accounts for 7% of the variance on perceptual reasoning and working memory. Collectively, and the three test-taking behaviors account for a modest amount of variance on perceptual reasoning, with Avoidance accounting for most of this variance. Furthermore, the three test-taking behaviors account for a significant amount of variance on working memory, with Inattentiveness accounting for most of this variance. The three test-taking behaviors do not influence performance on verbal comprehension and processing speed. Age also accounts for considerable variance on the four WISC-IV Spanish domains. (Contains 1 table.)