​ This study aimed to investigate the cognitive competencies of mathematics teachers about the International Study in Mathematics and Science (TIMSS). used the descriptive Survey methodology. The sample consisted of (227) male and female teachers in Amman schools. A test of (30) items was developed and divided into two sub domains: General knowledge and knowledge about the mathematical content of TIMSS test items. The results showed that the teachers' cognitive competencies about TIMSS regarding the two domains and the overall score is moderate, the results showed statistically significant differences according to experience, and gender within the content domain. In favor of experienced (10 years and more) compared to the experienced (less than 5 years), and in favor of females' teachers compared to the males. In light of the results, the researcher recommended the need to increase the awareness of mathematics teachers about TIMSS test.