Lean leadership could be the missing link between toolbox lean and a sustainable continuously improving organization. More and more enterprises realize that they have so far basically focused on the visible parts of lean production systems. Although process optimization with the various methods like kanban, 5S, SMED, FIFO and many more is very effective to achieve short term improvements, after a few years, the lean programs of many enterprises do not meet the expectations anymore. The common approach can be explained by using the 4P Model. It consists of 4 levels that are all necessary for a sustainable lean implementation. The levels are: philosophy (long-term thinking), process (eliminate waste), people and partner (respect, challenge and grow them) and problem solving (CIP and learning). All these terms are well- known. However, most enterprises merely focus on process. Eliminating waste in all processes has been preponderantly adopted, whereas the other 3Ps, the “invisible” parts of lean, are less easy to adopt but equally important for the sustainable implementation. Lean leadership addresses all 4Ps and provides a methodical system for the sustainable implementation and continuous improvement of lean production systems. It describes the cooperation of employees and leaders in their mutual striving for perfection. By now, many authors have identified the need for a lean leadership but only few holistic concepts exist. Especially lower and middle management lacks some clear advices and rules for lean leadership implementation. Therefore, some indicators for successful lean leadership were deduced from literature, study results, and practical experiences of lean implementation. The indicators were found in advices given on successful lean implementations, but particularly in mistakes and shortcomings. After reformulating the indicators into requirements for leaders, they were assigned to the five principles improvement culture, self-development, qualification, gemba, and hoshin kanri. These requirements shall help executives in realizing lean leadership.