This article describes the Decision Support System (DSS) software for identifying the best contractual delivery methods for megaprojects, based on the elements of risks, opportunities of investments and project constraints. A fuzzy-based multi-criterion decision-making technique is used to develop the DSS, to assist the client in the selection of the appropriate contractual delivery method. The system accounts for the relative importance of the various stakeholders in the different project stages. The system enables the client to depict his/her best choices (regarding project delivery methods and stakeholder entities) that would likely provide the best environs for the project to succeed. With such complicated system, the client can also investigate the specifics of the various project stages and study the effects of enhancements or deficiencies of the stakeholder entities capabilities. The system was developed and calibrated based on the results obtained from extensive surveys among key stakeholders in the UAE.