Abstract: The invention provides an electrosurgical tissue penetrating probe (e.g., a trocar) for use with surgical procedures such as a laproscopy. The trocar has a stylet disposed within the housing member, having an active electrode disposed on a distal end thereof to deliver electrosurgical energy to the target tissue in contact with the stylet. A return electrode is disposed on the housing member to form part of a return electrical path to the delivery electrosurgical energy. The invention also provides an electrosurgical trocar system having an impedance monitor and associated power regulating circuitry to control the amount of electrosurgical energy delivered to tissue so that the measured tissue impedance is maintained within a preselected range.