A parallel soil-structure interaction (SSI) model is presented for applications on distributed computer systems. Substructring method is applied to the SSI system and a coupled finite-infinite element based parallel computer program is developed. In the SSI system, infinite elements are used to represent the soil which extends to infinity. In this case, a large finite element mesh is required to define the near field for reliable predictions. The resulting large-scale problems are solved on distributed computer systems in this study. The domain is represented by separated substructures and an interface. The number of substructures are determined by the available processors in the parallel platform. To avoid the formation of large interface equations, smaller interface equations are distributed to processors while substructure contributions are performed. This saves a lot of memory storage and computational effort. Direct solution techniques are used for the solution of interface and substructure equation systems. The program is investigated through some example problems. The example problems exposed the need for solving large-scale problems in order to reach better results. The results of the example problems demonstrated the benefits of the parallel SSI algorithm. (C) 2003 Elsevier Science Ltd. All rights reserved.