The Study aimed at assessing and evaluating the items of the Mathematics test for grade seven as part of the Cognitive Development Program for the last three academic years (2012/2013 to 2014/2015) in the Sultanate of Oman. The evaluation process was concerned with the ratios of items that assess different cognitive levels as identified by Bloom and his colleagues. These levels are: Recall, Comprehension, Application, Analysis, Synthesis and Evaluation. This study also endeavors to verify the reliability of the test, the level of its difficulty, and the ability of the items in discriminating between students' performance. The sample of the study was composed of randomized sample of students' answer-papers related to the Mathematics test for grade seven as part of the Cognitive Development Program for the last three academic years (2012/2013 to 2014/2015). The total number of these papers was 9000. The researcher used a tool of two parts: the first part was a form to analyze tests questions in terms of their design (objective level) and the second part was a cognitive level (knowledge, application and high order skills). Another form was used to analyze the grade seven Mathematics tests in terms of availability of (rules) to compose and write objective questions. The criterion validity of the tests was calculated by comparing a sample of students results in the cognitive development tests with their results in normal Mathematics tests of grade seven every school year. The Pearson Correlation Coefficients for 2012/2013, 2013/2014 and 2014/2015 school years were (0.49), (0.54) and (0.55) respectively. This indicates that there is a significant correlation. The internal consistency of the test marks was calculated by using the Cronbach's alpha method and the consistency coefficients for 2012/2013, 2013/2014 and 2014/2015 school years were (0.55), (0.60) and (0.65) respectively. This indicates that there is a level of internal consistency less than what was expected when measuring cognitive skills. The results of the one-way analysis of variance (ANOVA) showed that there are differences of a statistical significance among the students with regard to their levels of attainment according to their marks obtained in Mathematics tests as part of the Cognitive Development Program as per gender and school year. The study concludes with a set of recommendations and proposals related to the theme of the study.