The history of tissue expansion, technique, indications, and complications are reviewed. A detailed review of delayed tissue expansion's histologic, biochemical, biomechanical, and physiologic changes in the skin is given. There is a net gain in epidermal tissue during delayed expansion. Recent experimental and clinical experience suggests that expansion for 1 to 2 weeks is just as effective as longer delayed expansion for 6 to 8 weeks. A new deviation from standard technique, intraoperative tissue expansion, may have significant implications for dermatologic surgery. Intraoperative tissue expansion is explored in relation to other commonly used techniques of intraoperative load cycling.