A thin skin flap is often required for optimal resurfacing of particular areas of the body such as oral lining, hands, and feet. Using wide and thin flaps provides a higher level of esthetic and functional results in reconstructive surgery. Recently, the authors also applied the thinning procedure for free SCIA/SIEA flaps. From 2003 to 2006, 11 patients underwent soft tissue reconstruction using thin free SCIA/SIEA flaps. In this procedure, deep subcutaneous fat tissue was removed totally while superficial subcutaneous tissue was thinned and a fat tissue layer was left under the skin to protect the subdermal network. All procedures were performed without using an operating microscope. The flap ranged 10 to 60 cm in length and from 6 to 55 cm in width. Ten flaps survived completely, while 1 occurrence of distal superficial necrosis was observed. No secondary flap defatting or revision was necessary. The free SCIA/SIEA flap may be prepared safely using a simple surgical procedure such as wide and thin flap in reconstructive surgery.