Due to particularities in the early stages of children developemnt, psychodiagnostic assessment of small children is based on the use of psychomotor development scales, and the assessment of intelligence in children younger than three years is not justified. In Croatia, because of the lack of appropriate intelligence tests, psychomotor development scales are used for the assessment of children up to the age of 6, despite the fact that there are no studies concerning the relationship of scores achieved on psychomotor development scales and scores achieved on intelligence tests. The absence of data regarding that relationship renders the prognosis of intelligence based on the scores obtained with psychomotor development scales questionable. The aim of this study was to investigate the relationship of scores obtained with Čuturic Development Test (RTČ) and those with Wechsler Intelligence Scale for Children (WISC) obtained immediately after or within certain time interval, and to determine whether there are differences in mentioned relationship regarding the age of the first application of the RTČ and regarding different clinical diagnoses. The study was conducted on the sample of 100 participants, 66 male and 34 female, with the average age of 68,18 months. The mental quotient data based on RTČ (Čuturić, 1987) and verbal, performance and full scale intelligence quotient data based on WISC (Wechsler, 1949) were collected. The correlation between RTČ scores and WISC full scale intelligence scores equals r = ,799 and is statistically significant (p<,01). The correlation between RTČ scores and WISC verbal intelligence scores equals r = ,757 and is statistically significant (p<,01). The correlation between RTČ scores and WISC performance intelligence scores equals r = ,761 and is statistically significant (p<,01). When observed through different categories (normal, borderline and subnormal achievment), scores obtained with RTČ and WISC do not matched. Contrary to the hypothesis, the age of the first application of the RTČ was not associate with scores obtained with RTČ and WISC. The hypothesis that the corellation of the scores obtained with RTČ and WISC will not differ in regard to different clinical diagnoses was confirmed.