With increasing public awareness of the environmental consequences of landfill operations, traditional Municipal Solid Waste (MSW) landfill technology, referred as sanitary landfilling, are facing formidable challenges. Local governments, municipalities and waste professionals are seeking more environmental-friendly alternatives to dispose of MSW by recycling, composting, anaerobic digestion and combustion. The resultant trade-offs, which inevitably lead to increased short term costs, call for more comprehensive economic analysis of different waste disposal alternatives, in particular based on social, economic and environmental justifications. This dissertation presents the development of an economic cost model for Australian MSW landfills. In order to facilitate the development of landfill economic cost model, the study presented in this dissertation first investigates the current status of landfill management and landfill economics through a landfill survey covering about 40 Australian local government authorities. The economics and management associated with the practice of MSW landfills are obtained and analysed. The cost information obtained from the survey serves as a basis for cost estimation or an evaluation of waste disposal alternatives. These include the costs of site establishment, operating costs, site closure costs and post-closure monitoring costs - referred to as direct costs of landfills. Secondly, the externalities associated with the landfill operations are examined and quantitatively evaluated. The externalities considered in this study comprise site disamenity, the potential traffic accidents and air pollution from MSW collection and transportation, the risks of leachate contamination and the effects of landfill gas emissions. A systematic approach which employs several evaluation techniques, has been developed to assess economic values of these so-called external costs of landfills. Based on the estimates of the direct and external costs, a computer-based spreadsheet model, referred to as Landfill Economic Model (LEM) has been developed to undertake landfill cost estimation. With landfilling being the dominant method for MSW disposal in Australia and worldwide, sanitary landfills serve as the baseline options for the model development. Bioreactor landfill technology, which is actively under investigation in Australia and other countries, is chosen as the alternative against the baseline option. The LEM consists of several modules representing the direct and external costs of individual physical process associated with the two MSW disposal technologies considered. These module can be used independently or linked together to present a sub-system of MSW disposal management. In the absence of locally specific data, the typical data for Australian conditions may be used as default values. A detailed case study is presented as an illustration of the implementation of the developed LEM. It comprises two parts. The first is cost development for sanitary landfills and bioreactor landfills, both including the associated direct and external costs. Although the cost estimates are limited to the hypothetical case, the methodology for the cost estimation can be applied to any landfill in Australia. The second is cost analysis. The analysis include data validation for sanitary landfill cost estimates, sensitivity analysis of the key parameters in the bioreactor landfill option and a comprehensive cost comparison for the two options considered. This lends credibility that the cost estimates which are presented reflect well the economics of a current landfill. The external cost estimates, despite the difficulties in, and a degree of arbitrariness regarding boundaries, are also found to be comparable to other reported estimates. The contribution of this dissertation is to present the economics of landfill on a broad basis and in particular, by taking social, economic and environmental factors into cost estimation. Based on a detailed examination of direct and external costs associated with landfill operations under current regulatory requirements, the developed LEM model provides a practically useful tool in conducting cost-benefit analysis of MSW disposal alternatives.