This book constitutes the refereed proceedings of the 8th International Conference on Mathematics of Program Construction, MPC 2006, held in Kuressaare, Estonia in July 2006, co-located with AMAST 2006, the 11th International Conference on Algebraic Methodology and Software Technology. The 22 revised full papers presented together with 3 invited talks were carefully reviewed and selected from 45 submissions. Issues addressed range from algorithmics to support for program construction in programming languages and systems. Topics of special interest are type systems, program analysis and transformation, programming language semantics, program logics.