Cannula anchor assemblies are disclosed which consist of a threaded cannula and a cannula anchor. The cannula anchor system allows for secure anchoring into the body wall, and proper cannula height adjustment prior to and during surgery. Sutures through the body wall may be secured to the cannula anchor either directly through the cannula anchor, or around suture posts attached therein. The cannula anchor also prevents excessive plunge of a trocar into the patient. The cannula anchor is generally configured with internal threads that mate with a threaded cannula.