The design of a seawall will inevitably involve an enormous amount of repetitive design calculations which is quite tedious and time consuming. In this paper, the development and verification of a program, tailored for use on IBM compatible microcomputers, for the computer-aided design of gravity type vertical seawall formed by precast concrete blocks are presented. The software is written in Pascal language using Turbo Pascal version 5.0 compiler which is a structured, high level language with integrated source level debugging. The forces due to water waves are calculated based on the Hong Kong meteorological conditions. It is written in such a way that it automatically computes forces and moments due to surcharge and soil pressure behind the seawall together with wind-generated wave forces and checks for the adequacy of the seawall configuration under various loading cases. Warning messages will be displayed if any stability criterion against sliding, overturning or bearing capacity is not satisfied and then expert advice will be furnished to the user in order to improve the seawall configuration to fulfill all the criteria.