This volume contains the proceedings of the Second International Symposium on Theoretical Aspects of Computer Science, held at Tohoku University, Japan in April 1994. This top-level international symposium on theoretical computer science is devoted to theoretical aspects of programming, programming languages and system, and parallel and distributed computation. The papers in the volume are grouped into sessions on: lambda calculus and programming; automated deduction; functional programming; objects and assignments; concurrency; term rewriting and process equivalence; type theory and programming; algebra, categories and linear logic; and subtyping, intersection and union types. The volume also includes seven invited talks and two open lectures.