A medical electrical lead having an elongated lead body and a fixation helix extending along a generally helical axis, mounted around the outer circumference of the lead body. The fixation helix has a free end spaced from and extending from the lead body for less than the circumference of the lead body. The lead body includes an additional component which provides a rotation stop extending from the outer circumference of the lead body and provides stop surface generally perpendicular to the axis of the helix.