This volume contains articles based on lectures given at the International Conference on Pseudo-differential Operators and Related Topics at Växjö University in Sweden from June 22 to June 25, 2005. Sixteen refereed articles by experts from Canada, Denmark, England, Italy, Japan, Mexico, Russia, Serbia and Montenegro, and Sweden are devoted to pseudo-differential operators and related topics. They cover a broad spectrum of topics such as partial differential equations, Wigner transforms, Weyl transforms on Euclidean spaces and Lie groups, mathematical physics, time-frequency analysis, frames and stochastic processes.