In metro-rail projects, excavation depths may reach more than 30 meters in the construction of underground stations. In such cases, the dominant proposed excavation support system is the diaphragm wall system. Secant piles, contiguous piles, berlin walls, and other systems may be proposed for use in substructures as external accesses with depths up to 15 meters. Selecting the appropriate excavation support system is a crucial challenge for builders and designers. Complex factors which are considered in the selection process and dependent on the subjective judgments of the construction practitioners based on their past expertise, create uncertainty and imprecision. Analytical Hierarchy Process (AHP), despite its popularity and wide use in the field of decision-making, is incapable of dealing with uncertainty in complex multi-criteria decision-making processes. To evaluate such complex decision-making problems, fuzzy set theory is combined with AHP in this study to use the fuzzy AHP (FAHP) technique in dealing with ambiguity and impression. To illustrate the applicability of the developed model, Heliopolis, and Kit Kat metro stations are presented, as case studies, in the greater Cairo Metro. It was concluded that the diaphragm wall system, although it is still more costly but preferable.