An electrosurgical instrument is provided for the treatment of tissue, the instrument (3) including a shaft (14) and a tip portion including at least one electrode (16), located at the distal end of the shaft. A fluid impermeable sheath (25) covers at least a proportion of the shaft and extends to the tip portion where it terminates in a distal end portion (26). A metallic shroud (29) is provided, comprising an annular ring portion (30) and a rearwardly extending cylindrical portion (31). The ring portion (30) is connected to the tip portion, and the cylindrical portion (31) overlies the distal end portion (26) of the sheath (25) so as to prevent ingress of fluids at the distal end portion of the sheath.