The paper considers the main results and some educational implications of the TIMSS 2003 assessment conducted in Serbia in the fields of the science achievement of Serbian eighth grade students and the science curriculum context of their achievement. There were 4264 students in the sample. It was confirmed that Serbian eighth graders had made average scale score of 468 points in the science, and with this achievement they are placed in the zone of the top of low international benchmarking level, very close to the point of intermediate benchmark. The average science achievement of the Serbian eighth graders is somewhat below the general international science achievement. The best results were achieved in the science content domain of "chemistry," and the lower results in the content domain of "environmental science." Across the defined science cognitive domains, it was confirmed that the Serbian students had achieved the best results in cognitive domain of "factual knowledge" and weaker results in "reasoning and analysis." The achieved results raise many questions about contents of the science curriculum in Serbia, its overall quality and basic characteristics of its implementation. These results can be used to improve the science curricula and teaching in Serbian primary school. (Contains 13 tables.) [This article is the result of the project "Education for knowledge-based society" No 149001 (2006-2010), financially supported by the Ministry for Science and Environmental Protection Republic of Serbia.]