Tissue expansion has now achieved an important place in reconstructive surgery, since the first experiments about 10-15 years ago. Expanded tissue used in reconstruction is usually excellently matched for colour, thickness, elasticity and other physical properties. This is particularly important in reconstructions in the head and neck region. Tissue expansion is also used increasingly for breast reconstruction all over the world. It is now the most common procedure for breast reconstruction in USA. Various options using either a temporary or a permanent expander are discussed.