This work presents a fuzzy optimisation model for the synthesis of refinery hydrogen networks under uncertainty. Based on a generic superstructure that incorporates all the possible connections between the hydrogen system elements (sources, sinks, compressors etc.), the mathematical formulation consists mainly of flowrate and impurity load balances, where fuzzy intervals are introduced to account for parametric uncertainties. Pressure constraints and the optimal placement of compressors are also taken into account. A case study is presented to illustrate the proposed approach.