Tissue expanders are widely used in the reconstruction of tissue wounds. This study aims to demonstrate how to choose the correct size of rectangular expander in relation to wound size and the maximum advancement technique for wound coverage in order to achieve a successful outcome. The present study included patients who were operated on between January 2013 and January 2017. The expander height chosen was more than half the length of the wound and the expander width was chosen to be as wide as possible, based on the width of the wound. The expander was placed in a site adjacent to the wound. Maximum advancement method was used to achieve coverage of the wound. A total of 19 patients were included in the study, mean age 17.5 (range: 11-25) years. Indication included burn scar (n=14) and congenital nevus (n=5). The tissue expander was inserted into the scalp in 17 patients and supraclavicular area in two patients. A successful wound repair was achieved with the planned flaps in all patients. In expansion using rectangular expanders, the required expanded skin is gained through the height of the expanded tissue. Thus, expander size should be preoperatively planned to ensure the height of expanded tissue would be, at least, half of the wound length. Maximum benefit will be achieved from the expanded tissue through the correct placement of expanded tissue lateral flaps.