After the success of various international experiments of adopting preventive conservation approaches for safeguarding the cultural heritage such as Monumentenwacht Vlaanderen in Belgium, and Netherlands, and La consrvazione programmata in Italy, many countries attempt to put such strategies for protecting their heritage. During the last three decades or less, many monuments and heritage buildings in Mosul old city have been deteriorated progressively due to many factors the most important of which is the lack of monitoring and controlling procedures for preserving these irreplaceable outstanding constructions. Preventive conservation describes research and interventions aiming at reducing deterioration rates and minimizing risks to the constructions. It aims to identify and reduce potential hazards to cultural artifacts with thoughtful control of their surroundings, and it attempts to mitigate the occurrence of damage and deterioration through research and the implementation of procedures which enhance the safety of cultural objects and buildings. The absence of a comprehensible and efficient preservation protective policy for the responsible institutions of conservation of Mosul built heritage is a critical issue. The research aims to compare the current conservation policy of these institutions with international counterparts, and to put guidelines and recommendations for preparing a preventive conservation plan for the cultural heritage of Mosul Old City, which are represented by controlling its vital aspects such as managing of environment, risk, documentation, schedule investigation, information, regulation, human resources, and communication. The paper methodology adopts a comparative analytical study between several successful international experiments in preventive conservation field and the current existing procedures of the conservation of the Mosul built heritage.