Aim: The aim of the study was to examine (1) the perceptions on core competencies of healthcare professionals working at clinical settings in Oman and (2) which demo graphic characteristics explain the overall core competency. Design: A cross-sectional design. Methods: Healthcare Professional Core Competency Instrument, consisting of 11 sub-scales with 81 items, was distributed to healthcare professionals (n = 1,543; 826 nurses and 717 physicians) who worked at primary, secondary and tertiary healthcare institutions. Descriptive statistics, t-test, ANOVA and linear regression were used for data analysis. Results: Altogether 1,078 healthcare professionals (628 nurses and 450 physicians) re sponded representing 70% overall response rate. Healthcare professionals perceived their overall core competence as excellent, safety being the highest, and research and evidence-based practice was the lowest. The multiple linear regression analysis revealed that ethnicity, gender and years of working experience were the characters that explained the overall core competence, where expatriate senior professionals reported higher competency levels compared with counterparts.