Iraq faces significant challenges in hydropolitics and water resources management. Against this backdrop, the present study examines how the mismanagement of water resources in Iraq has contributed to the emergence of hydropolitical challenges between Iraq and the Islamic Republic of Iran. The central hypothesis posits that Iraq’s inefficient and unsustainable water management practices have intensified hydropolitical tensions with Iran. Methodologically, the study is applied and problem-oriented, employing a descriptive–analytical approach. The findings reveal that several interrelated factors have significantly influenced hydropolitical relations between the two countries, including inadequate assessment and inefficient utilization of water resources, deficiencies in water infrastructure, and the absence of effective water diplomacy to promote sustainable water governance in Iraq. These structural shortcomings have not only aggravated Iraq’s domestic water-related challenges but have also generated significant transboundary hydropolitical consequences for Iran. The study concludes that, unless comprehensive reforms in water resources management and bilateral water cooperation are undertaken, hydropolitical tensions between Iran and Iraq are likely to intensify in the coming years.