The main aim of this study is to investigate the validity and reliability of the A-2 and 3-5 forms of the DISCOVER Spatial Analytical Assessment. For validity analysis 51 gifted and 51 average students were chosen as the target group and for reliability, 49 average students were included in this study. The students were administered the SAIA of DISCOVER Assessment, the Raven's SPM Test and the Inquiry Form. In order to identify psychometric characteristics of DISCOVER SAIA, Pearson and Discriminant Function analyses were used. The study showed that the two variables of the DISCOVER SAIA's 3-5 form; the number of pages and the degree of giftedness respectively were found to be reliable. It was also found that 61.9% of original group cases were correctly classified by DISCOVER SAIA A-2 form and 65.5% by 3-5 form.