Technology assessment help managers to accomplish an overall evaluation of technologic options and to identify investment priorities. Making such priority has become of great importance owing to ever-increasing costs of technological research and development and resource scarcity. Technology Attractiveness Assessment, as a primary step of Technology assessment process, has been considered in this paper. Based on the multi-criteria decision-making approach and because of the inherent uncertainty in the preference information on attributes, a Grey-MADM based methodology has been utilized in this paper to assess the technology attractiveness and rank the upstream industry technological options. Its application to a real case problem has been described step by step. The results of the case study showed that "Nano Coating for Drilling Tools", "Petroleum Systems Model Building" and "Integrated Asset Modelling" are the most attractive upstream technologies.