Abstract The Bosphorus (Istanbul Strait) is the most critical passage in the World for vessels passing through; mainly due to its narrowness, its shape with several sharp turns and headlands which limit to have an extended sight for a proper look-out and close the view behind, complex as well as day-to-day changing nature of its currents. The localities with high risk for grounding or stranding in the Bosphorus are: Umur Banki, Yenikoy,Bebek, Kandilli; for collisions the evidence suggests that critical areas are Besiktas, Bebek, Kandilli, Kanlica, Yeniköy,Beykoz and Sariyer. The Montreux Convention relating to freedom of passage and navigation establishes and regulates the regime with certain formalities for a merchant and naval vessel since 1936. The Strait is kept open for shipping traffic day and night, and serves as an international waterway of commercial importance. Turkish Government has taken constructive steps forward to enhance navigation and environmental safety in the Region, the Strait of Istanbul inclusive, by implementing maritime traffic regulations and setting VTMIS which is fully operational since mid-2003. So far, the outcome is promising, and the annual rate of casualty has decreased significantly. However, it is too early to judge how far the VTMIS has been effective in achieving the ultimate goal.