This dissertation explored the Best Practices of Executive Coaches who coach C-Level Executives. The set of best practices developed was differentiated from best practices as applied with middle-manager executive clients. C-level executives were deemed to have a role within the organization with unusual influence and complexity and thus worthy of a separate (or higher order) set of best practices. The qualitative research deemed from 11 interviews supported such a claim with the development of two primary best practice categories for coaches working with C-level executives: Higher-level processing and Trusted Advisor and Peer. Two other sets of practices emerged from the data as well: Basic coaching best practices applicable to any coaching engagement (and supportive of existing best practice literature) and client best practices, a set of best practices for the client to utilize as a means of sustained professional and organizational growth. This study also investigated the notion that coaches working at the higher level of C-level coaching should be at a higher level of coaching excellence (i.e., be a "great" as opposed to a "good" coach). This area was deemed to be worthy of further discussion and research. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]