The treatment of photoaging has seen dramatic progress, from the medical, such as topical retinoids, to the surgical, such as the use of ablative laser skin resurfacing (LSR). Laser skin resurfacing is best documented with carbon dioxide (CO2) lasers. There are clearly immediate improvements after the procedure, but the full benefit continues to appear over several months. Wound healing appears to be an intrinsic part of the therapeutic benefit to patients. Despite more than a decade of LSR experience, we do not understand the specific changes; the actual mechanism of improvement is not entirely clear. This issue was addressed by examining the science behind LSR in a comprehensive review providing a basis for understanding part of the problem.1