The Blunt Tip Trocar consists of a blunt obturator and a valve body/cannula assembly. The valve body/cannula assembly contains an internal flapper valve and seal to prevent gas leakage when instruments are inserted or withdrawn. The Blunt Tip Trocar includes built-in converters to allow insertion of instruments of various diameters. In addition, the device has an external one-way valve for gas insufflation. To minimize leakage and secure the trocar, the distal end of the sleeve has a balloon which is complemented by the proximal foam sponge/collar assembly. A syringe is provided for inflation/deflation of the balloon