In the preferred embodiment, the surfaces of the instrument that are to remain uncoated are first masked. The unmasked surfaces are roughened and then dipped in a liquid silicone. The parylene coating is then applied by vacuum vapor phase deposition and annealed. A parylene coating can also be applied to portions of the electrosurgical implement for insulation. A thin parylene coating can be applied to the blade of the instrument as a non-stick coating for easier cleaning. If the instrument is an endoscopic electrosurgical instrument used with a trocar sleeve having a valve to receive the shaft, wear between the valve and the shaft can be reduced by applying a parylene coating to the interior surface of the valve.