In this paper an eco-efficiency analysis methodology that takes into account Life Cycle Assessment (LCA) and fuzzy logic is presented. It consists of four stages: (1) perform LCA and basic cost analysis, (2) normalize the environmental and economic impact categories results, (3) integrate economic and environmental impact categories by means of a fuzzy treatment and (4) obtaining the fuzzy eco-efficiency index. The result is a preference hierarchy that indicates an order of scenarios according to their degree of eco-efficiency. The methodology proposed is applied to a Mexican SME: a plastic products manufacturer. Six different supplier locations of polypropylene were considered: United States of America (transporting by land and by water), China, Singapore, Europe, and United Arab Emirates. The robustness of the methodological framework was tested by means of a comparative analysis with a decision surface graph, an eco-efficiency index, and random runs to prove their variability. Results show that USA is the most preferable supplier location when polypropylene is transported by land. The comparative analysis with the random series results and the decision surface graph, allowed to corroborate the stability of the fuzzy preference orders and to identify clusters of scenarios with an equally eco-efficient performance. Thus, the robustness of the methodology proposed was validated.