As an active developer, researcher, and practitioner of ACT and transcendental meditation (TM), Eifert is coauthor of several popular books, including the highly praised practitioner's treatment guide, Acceptance and Commitment Therapy for Anxiety Disorders, as well as several ACT books for the public: ACT on Life Not on Anger, Your Life on Purpose, and The Anorexia Workbook. He has also authored and coauthored several books in German.
Eifert regularly gives workshops and talks around the world, teaching ACT to both the public and professionals to help people end psychological suffering and lead more fulfilling lives. His workshops have been praised as inspiring, humorous, and empowering, and are renowned for their authenticity, clarity, and practical usefulness.