The request to organize under its patronage at Poitiers in 1998 a Symposium entitled "Advanced Optical Methods and Applications in Solid Mechanics" by the International Union of Theoretical and Applied Mechanics (I.U.T.A.M.) was well received for the following two reasons. First, for nearly 20 years no Symposium devoted to optical methods in solids had been organized. Second, recent advances in digital image processing provided many new applications which are described in the following. We have the honour to present here the proceedings of this Symposium. st th The Symposium took place from...