The successful comissioning of an economically viable mining project can only be achived once a complex range of interrelated technical, financial and legal issues have been considered at the planning stage. The mining feasibility study provides the formal framework for this exercise, involving detailed engineering design and cost estimates undertaken by a large project team. Before embarking on a full feasibility study, however, there are considerable advantages in a small group of experienced professionals undertaking a preliminary feasibility study. The foundation of the preliminary feasibility study in the development of geological model which forms the basis of the reserve estimations. Geostatistical techniques can then be applied to determine if the deposit has been corerectly sampled and provide and indication of the uncertanity associated with the estimated grade. The whole inegrity of the project will be called into question if the geostatistician has to place any qualification on the reliability of the sampling programme. Once the geometrie form and size of the deposit and the concentration of the metal or mineral has been estabilised, an initial design for the mine and mineral processing stages can be considered. It is particulary important that the rate of production should be on a scale which is appropriate to the size of the ore body. A mine life much in excess of 10 years does not enhance the net present value of the project, while too short a mine life does not permit adequate return on capital. The leagl framework of the project incorporate environmental constraints, mining permits and tex provisions. Regaldless of the technical merits of the project, these will impact on any decision to proceed with the venture. A simple discount cash study to establish the overalI financial viability of the project and undertake a basic sensivity analysis. A preliminary feasibility study can be based on same broadly based engineering ascumptions provided a reliable reserve estimation has been undertaken. This permits key financial and legal issuees to be identifies and the general economic viability of the project to be asessed. This then provides the framework for the rule feasibility study and the justification to undertake additional expenditure on engineering design.