Customer complaints serve as a valuable source of market intelligence, enabling companies to address the root causes of problems and improve their products and services. Businesses can enhance customer satisfaction and overall organizational performance byleveraging customer feedback. Accordingly, the purpose of this research was to identify the key factors affecting the management of customer complaints and their prioritization in Iraq's oil industry. The present research is a mixed method in terms of data collection (qualitative-quantitative). First, semi-structured interviews with 8 experts were conducted in the qualitative part. To find themes, qualitative data from reviewing theoretical foundations and interviews with experts were coded and categorizedusing theme analysis. Then, in the quantitative part, the AHP method and Expert Choice software were used to prioritize the factors. For this purpose, the paired comparison questionnaire was distributed among 20 people. The results of the quantitative analysis showed that the factors affecting customer complaints respectively include 5 main-categories of customer-related factors, factors related to product performance, factors affecting personnel, and process-related factors and at last management-related factors.