The study evaluated the suitability of primary school teachers' professional development policy implementation conceptualization of targets, reflective contents, process, methods and contexts in which it occurs in Oromia. The researchers used a mixed method with concurrent triangulation design. The researchers selected a total of 618 samples of the study using different sampling techniques such as purposive, convenience, stratified and simple random sampling techniques. The data were collected from primary sources of data such as teachers, mentors, principals, supervisors, coordinating committees and parents using questionnaires, interview, focus group discussion, document examination and observation. Then, the researchers analyzed the data using mean, standard deviation, one-way ANOVA and post hock test, and thematic narration. The study showed that both veteran and novice teachers were less able to conceptualize and contextualize their professional development practices to the existing phenomena in the schools under investigation. Teachers' professional development practices were powerless to update professional competencies and improve professional and innovative pedagogical practices in classrooms. In addition, the professional development contents and activities were repetitive from time to time. Primary school teachers were not learning proficiently from continuous professional development practices to ensure basic and specific professional competencies required in classrooms. The implementations of reflective activities such as action researches, classroom observation, differentiate learning; collaborative learning, microteaching and lesson studies couldn't contribute to practical changes. Teachers weren't actively participating in professional development because of lack of conceptualization and contextualization of reflective activities to improve professional competencies although they are transformative intellectuals. Therefore, teachers, mentors, principals, and cluster supervisors should use face-to-face learning and digital learning strategies to improve instructional practices in classrooms, and values and prestige of teaching profession. Likewise, the study forecasts the requirement of context specific policy framework and practical toolkit for newly deployed and experienced teachers rather than focusing on the generic policy document.