Coaching is increasingly establishing itself as an effective personnel development tool. For this, it is important to understand what coaching is and to know the occasions when coaching is used and what significance coaching has in the context of executive development. Various research works have shown that coaching has diverse positive effects. In addition, coaching can also produce unwanted side effects. Furthermore, some factors of success for successful coaching can be found, such as the relationship quality between coach and client or the credibility of the coach. From this, recommendations for action can be derived for practice, to ensure as successful and side effect-free coaching as possible. This includes both suggestions for the selection of the suitable coach as well as hints for the selection of the client and for the organizational support.