Purpose The purpose of this paper is to report a research conducted to apply fuzzy axiomatic design approach for selecting the design alternatives of an overflow valve. Design/methodology/approach The approach started with the identification of functional requirements (FRs) and design parameters (DPs) and the relationship between them to select the best design alternative. Fuzzy analytical hierarchy process was used to calculate the weightage of FRs. The independence and information axioms were being deployed to validate the selection process. Findings The most important FRs being identified include “improve manufacturability and adaptability”, “improve ease of operation” and “provide strength and reliability”. The most important DPs are design unification on washer and outlet valve, material selection for improving the strength and reliability and pressure change to check whether the valve is withstanding the pressure using flow analysis. The best design alternative (A1) which deals with material substitution is being implemented in the case organization. The proposed methodology also enables contemporary design engineers to effectively select the best design among a set of alternatives in a fuzzy environment. Research limitations/implications This paper presents the application of fuzzy axiomatic design for selecting the best design alternative of an overflow valve. The identified best design is being subjected to implementation in the case organization. Practical implications The industry decision makers were involved throughout the conduct of the study. Hence, the inferences derived from the study possess practical feasibility. Originality/value The application of the fuzzy axiomatic design approach for selecting the best design alternative of an overflow valve is the original contribution of the authors. Also, the practical feasibility of the approach is also being exemplified. © Emerald Group Publishing Limited