Port State Control Port State Control is one of the best methods to control the safety of vessels, to identify non- standard vessels, and to prevent the movement of them. Port State Control is a process of performing international conventions, rules and regulations, and instructions related to maritime safety and marine environment protection on foreign – flag vessels. Iran Ports and Maritime Organization is in charge of Port State Control and Flag State Control. This organization is also responsible for controlling non-convention vessels (GT<500).Analyzing available data show that problems of the vessels can be divided into three categories: 1. Problems related to the safety;2. Problems related to the marine environment protection;3. Problems related to the machineries.