The objective of the thesis is to examine computer applications to the sales, income, and cost approaches to valuation. The author describes and evaluates computer programs suitable for the storage and retrieval of sales data, the analysis of 'net rate' information for houses, and the adjustment of land sales for size variations. The use of multiple regression analysis in the sales approach to valuation is reviewed, and this methodology is then applied to the valuation of a group of home units and single family homes. Variables were selected from the Valuation Department sales data base and multiple listing information. The inclusion of the existing rating valuation significantly improved the predictive ability of the regression equations. Several microcomputer applications to the income approach to valuation are discussed in the context of discounted cash flow. These include programs that compute residual land value for hypothetical developments and the optimum building for a site. A case study approach is used to demonstrate the application of net present value, internal rate of return, and financial management rate of return approaches to valuation. Two computer programs designed to estimate the replacement cost of buildings utilise costing information based on the New Zealand Institute of Valuers modal house. One of these programs calculates the replacement cost of a variety of farm sheds, and the other program calculates the replacement cost of houses. The author concludes that computer assistance offers considerable potential benefits to valuers for the storage and retrieval of sales information and for automating many aspects of the valuation process.