Psychometric properties of the test of non-verbal intelligence (TONI-4) for students of the first cycle of basic education in Muscat Governorate Laila Hamood Mohammed Al Manji This study aimed to know the psychometric properties of the test of non-verbal intelligence (TONI-4) on a sample (N = 715) of students enrolled in government schools in the Governorate of Muscat. They ranged between six to nine years during the academic year 2019/2020. To achieve the goal of the study, the sample consisted of boys and girls from cycle one of classes. The study used appropriate statistical methods to verify the assumptions of the item response theory (Unidimensionality, local independence, Item fit). The validity of the test was also verified in a number of ways, like: criterion validity, factorial validity, concurrent validity, and discriminant/divergent validity. The reliability of the test was also verified by the Cronbach's alpha and the reliability factor according to the Item response theory. The results indicated that the Test of Non-verbal intelligence (TONI-4) has an acceptable degree of reliability and validity.