The purpose of this study was to assess the application of elements of constructivist strategies in the teaching and learning process of the upper primary school sciences in the Addis Ababa Administrative Region government schools. The sources of data were grade seven science (Biology, Chemistry, and Physics) teachers and their classrooms. Three data collection instruments were used: classroom observation, questionnaire, and interview. Accordingly, 12 classrooms were observed, 48 teachers (including those observed) filled questionnaires and 4 teachers (from those observed) were interviewed. The results of the study revealed that the teachers lacked the necessary knowledge base to use elements of constructivist strategies in their classrooms. About 30% of the respondents rated 'strongly disagree' and' disagree' on very important issues related to the strategies with only 24.8% strong agreement. Therefore, it can be said that most of the teachers are guided by traditional philosophies and theories of learning. However, it is found out that these teachers have the necessary attitude to use the strategies. About 98% (with mean value 2.68) rated that the strategies/techniques as 'very much useful' and 'useful' for the teaching and learning processes in their classrooms The assessment regarding the extent of use of these strategies have also shown that the strategies are only rarely and sometimes used in most upper-primary science classrooms. Among the observed teachers, only 5.83% of them found applying them very well. The other 28.33% applied them moderately and 36.66% not applied them at all. . The analysis of the data collected through questionnaire has also revealed that about 50% of the respondent teachers are only rarely and sometimes applying, and about 10% do not apply them at all. However, about 30% of them applied frequently and always. The most serious factors affecting the use of elements of constructivist strategies are found to be: the lack of facilities such as the laboratories and laboratory resources; the classroom conditions, in general, and also the large number of students in a class; student's lack of interest and the textbook/the curriculum. Thus, urgent in-service training through workshops, and also small-scale training programs should be given to the upper-primary science teachers on modern theories of learning, parlicularly on the philosophical bases to teach science and also on how to incorporate elements of constructivist strategies into their classroom teaching. The stakeholders, the government and also the general public should seriously think upon providing the necessary facilities. Science teaching should also focus on student's developments of knowledge, skills in science and also attitudes and interest in science. The serious considerations the textbook designers give to modern theories and models of learning during the designing of the textbooks will also be very crucial.