This study examines the principle of preventing environmental harm, which seeks to avert damage before it occurs by implementing proactive measures to mitigate environmental pollution. These preventive measures constitute a framework of principles that guide management in safeguarding the environment from contamination. The principle of environmental harm prevention serves as a cornerstone in environmental protection, necessitating management's adherence to it to prevent detrimental human activities. Both the Iraqi and comparative constitutions affirm the individual's right to a healthy and unpolluted environment, thereby granting environmental rights significant constitutional status. Consequently, the constitution imposes a binding obligation on the state and management to uphold and safeguard the environment against harm. This study explores the principle of environmental harm prevention by dividing the analysis into two sections. The first section elucidates the concept of this principle, the general principles governing it, and its areas of application, while the second section examines the procedures for its implementation.