This Practice Note, written by Victoria Mahon de Palacios of Wedlake Bell, sets out the advantages, disadvantages and limitations of advance decisions (sometimes referred to as living Wills) and the alternative of a health and welfare lasting power of attorney (LPA), possibly alongside an advance statement. The key advantages are the ability to provide certainty to the decision maker, to provide a written record of wishes and the fact that the advance decision is effective immediately once signed. The disadvantages are the fact that there is no central register, the difficulty of ensuring an advance decision is applicable to future and changing circumstances and the fact that an advance decision can be invalidated by the decision maker’s later behaviour.