An electrosurgical suction coagulator is disclosed having improved thermal insulation between the active electrode and adjacent tissue. In embodiments, passive insulation is used to control the transfer of thermal energy from an electrosurgical electrode into surrounding tissue. Braided, closed-sell foam material, and open cell foam materials may be used to thermally insulate the outer surface of a suction coagulator shaft from an inner electrode. In embodiments, a suction coagulator shaft includes an external covering formed from open-cell foam material, which may be saturated with a coolant, such as water or saline, to increase the thermal mass of the shaft. In other embodiments, active cooling delivers coolant to the operative site. In yet other embodiments, a suction coagulator shaft includes a cooling jacket through which coolant is passed to actively cool the instrument. The improved electrosurgical suction coagulator disclosed herein may have a reduced operating surface temperatures which may result in reduced risk of undesirable effects to adjacent tissue, and may result in reduced operative times and improved patient outcomes.