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Objective: This is a standardization and norm study of Test of Nonverbal Intelligence-3 (TONI-3) in 6-11 age Turk-ish children sample. TONI-3 was developed to asses general non-verbal mental ability of 6 to 89 age people thus it is independent of language. TONI-3 has two parallel forms (Form A, Form B), both including 45-test items. Meth-ods: Participants were selected by stratified sampling method from schools, which have different socioeconomic levels. The participants were 631 elementary school students. Of 631, 320 were girl, 311 were boy between the ages of 72-132 months. Analyses were done for 10 age groups, each 6-month interval. Results: Internal-consis-tency reliability coefficient Kuder Richardson-20 was found between the range of 0.86 and 0.95 for Form A, 0.90, and 0.93 for Form B. The parallel forms reliability coefficient was found 0.80 for all age groups. Test-retest reliability coefficient was calculated from data collected with time lapse of 30 days and found 0.65 for Form A and, 0.70 for Form B. Criterion-related validity was inspected by correlating TONI-3 with Raven Progressive Matrices Test and the results were 0.79 for Form A and 0.82 for Form B. Other criterion-related validity results were, between academic success and TONI-3 0.52 for Form A 0.49 for Form B; Wechsler Intelligence Scale for Children-R Block Design subtest and TONI-3 0.47 for Form A, 0.51 for Form B. Conclusion: TONI-3 was found reliable and valid for Turkish children age of between 6-11 [Anadolu Psikiyatri Derg 2018; 19(0.100): 76-83]