This volume contains the proceedings of the Second International Conference on Algebraic Methodology and Software Technology (AMAST '91). The aim of the AMAST conferences is to promote the use of algebraic methodology as a foundation for software technology, and to examine how it can be used to provide practical mathematical alternatives to the ad hoc methods commonly used in software development. In particular the conferences provide a showcase for software systems which have been developed in this way, focusing on the conceptual developments which made them possible. The resulting volume covers a variety of software development issues, and testifies to the versatility of algebraic methods when used as conceptual tools in the software development process. It features a distinguished collection of invited papers from leading researchers in the field, many of which break new ground, or represent an important step forward in current research. Among the specific topics covered are: language design; compiler construction; software testing; symbolic computation and partial evaluation; incremental implementation; and the verification of programme and specification properties.