This paper presents the main results of the international study of students’ mathematics and science achievement TIMSS 2011. The focus is on presentation and discussion of the results achieved by Serbian students. In Serbia, this study was conducted in the fourth grade of primary school on a nationally representative sample of students - a total of 4379 students from 156 primary schools were tested, i.e. 219 classes. The average achievement of students from Serbia was 516 points in mathematics and in science, which in both cases represents achievement that is significantly higher than the center point of the TIMSS 4th grade scale. The paper also presents results according to content domains, differences in achievement between boys and girls, as well as students’ distribution according to international benchmarks. The results are observed from the view point of overlapping of the Serbian curricula and the TIMSS test. Overall, these results can be seen as encouraging indicators of the Serbian education system for the first education cycle, particularly if we bear in mind relatively poor performance of students in higher grades in Serbia which had been shown in various previous studies. Since TIMSS findings should primarily be used in planning the development of education, the concluding part discusses the importance of regular participation of Serbia in international studies of this kind, as well as the importance of greater involvement of domestic researchers in analysis of available international databases. [Projekat Ministarstva nauke Republike Srbije, br. 47008: Vrednovanje postignuća učenika u matematici i prirodnim naukama - TIMSS 2011, Unapređivanje kvaliteta i dostupnosti obrazovanja u procesima modernizacije Srbije i br. 179034: Od podsticanja inicijative, saradnje i stvaralaštva u obrazovanju do novih uloga i identiteta u društvu]