T This study seeks to explore the most common ethical issues in Gulf Cooperation countries (GCC) construction industry. Prior to this study, no research has been done in the entire region to identify the prevalent ethical issues in the region’s construction sector. A survey was conducted among construction professionals in the region. Exploratory Factor Analysis (EFA) with Monte Carlo PCA for parallel analysis revealed that fraud, delayed payments, tax avoidance, poor quality work, conflicts of interests, and intimidation were the most prevalent ethical issues within the GCC construction sector. It was also found that significant differences exists between the Middle East and North African (MENA) respondents and Non-Middle East (Non-MENA) expatriates in the region. The results show that unethical practices are prevalent within the region despite the efforts of Professional Engineering Institutions (PEIs) to educate their members. The differences between MENA and Non-MENA respondents seem to indicate the influence of culture on perceptions of ethical issues. Consequently, the findings should be interpreted within the context of the region. PEIs may need to improve on the trainings offered to members. Though exploratory in nature, the results represent the views of qualified professionals working in the region.