This study aims to reveal the degree of possession of the core professional competencies for teaching, in compliance with the global quality standards for preparing teachers, among Islamic education teachers in the primary schools in the Sultanate of Oman. In order to achieve the study’s objective, a list comprising the professional competencies of Islamic education teachers has been developed while ensuring its reliability to Cronbach’s alpha value (0.979). The study’s sample includes 852 individuals. Its results showed that the teacher’s competencies are divided into seven axes namely: personal characteristics, lesson planning, lesson implementation, classroom management, social engagement, usage of educational technologies, and consolidation of the citizenship principle. The latter registered the highest arithmetic mean (4.56) while the usage of educational technologies registered the lowest arithmetic mean (3.43). The results also showed statistically significant differences (α=0.05) between the arithmetic averages of responses by the study sample attributed to the variable of gender (in favor of the females), the variable of function (in favor of the Islamic education teacher in comparison with the senior teacher and educational supervisor), and the variable of educational stage. All axes were in favor of the basic education phase (from the fifth to the 10th grade) in comparison with the post-basic education phase (11-12), except for the “consolidation of the citizenship principle” axe, which came in favor of the second cycle of the basic education phase. In light of these results, the study recommended the preparation of training portfolios to train Islamic education teachers and equip them with the professional competencies and teaching techniques.