The results of Romanian students at international comparative TIMSS and PISA tests have constantly proven to be unsatisfactory. The present paper aims at analyzing the school syllabi "Mathematics and Environment exploration", "Environmental Education" and "Natural Sciences" studied during primary education in Romania and the Sciences curricula on which the TIMSS inquiry is based. The goal of this comparative analysis has been to provide themes of reflection for the conceivers of school syllabi in Sciences. For analysis the Romanian school curricula of Primary level we identified that knowledge ("content domain") and the abilities involved in building new knowledge (cognitive dimension and scientific inquiry process) are considered necessary to Fourth grade students by TIMSS curriculum. The analysis of school syllabi on which the study of science is carried out demonstrates that Romanian Fourth grade students have developed, based on these curricula, less scientific knowledge and skills than those investigated by the TIMSS inquiry. The main conclusions of this study are that the school syllabi for primary education in Romania require, without exception, re-evaluation and that the study of Sciences needs to rely on the scientific inquiry process to a large extent.