In recent years environmental-friendly Mercury free Xenon HID lamp - D3 and D4 respectively with and without integrated igniter - were introduced in the automotive headlighting market. This market introduction was primarily driven by an increased concern for the environment by all stakeholders in car industry including the end-users. Furthermore, ordered by public authorities world wide, via new environmental legislation rules, Mercury free Xenon HID lamps will take over an important part of the Xenon HID market in due time.Within this perspective this paper will give an overview about technical backgrounds of Mercury free Xenon HID lamp performance. Next to light technical aspects the electrical interfaces between lamp and electronic driver are included. Furthermore, new developments in terms of satisfying carmakers requests on environmental aspects, electromagnetic compatibility and application flexibility will be discussed.The paper can be seen as a follow up of the previous publications in HID technology for headlighting. It will end up with an outlook of further progress in Mercury free Xenon HID lighting.