The literature pertaining to intelligence assessment reveals an ongoing discussion about the areas of intelligence captured by nonverbal tests. To date, few studies have investigated the criterion validity of the Test of Nonverbal Intelligence, Third Edition (TONI-3). The present study investigates the concurrent validity of the TONI-3 in a sample of children at an outpatient medical facility. Scores from the TONI-3 are moderately positively correlated with the Full Scale IQ of the Wechsler Intelligence Scale for Children-Fourth Edition (WISC-IV). The TONI-3 demonstrates a strong positive correlation with the Matrix Reasoning subtest of the WISC-IV. The results indicate positive relationships between the TONI-3 and measures that tap into other areas of intelligence, such as verbal abilities and processing speed. Relationships among the variables are not distinct enough to suggest specificity in terms of testing a particular ability area. Limitations and implications for intelligence assessment are discussed. (Contains 3 tables.)