Abstract This paper deals with the problem of non-fragile H ∞ filtering for continuous-time systems with time-varying delays and norm-bounded parameter uncertainties. The non-fragile H ∞ filter to be designed is assumed to include the additive gain variations which result from inaccuracies in filter implementations. By choosing suitable Lyapunov-Krasovskii functional and using Wirtinger-based integral inequality, sufficient conditions for the existence of the designed H ∞ filters are expressed in terms of linear matrix inequalities (LMIs). Finally, in order to illustrate the effect of the proposed method, a vertical take-off and landing (VTOL) helicopter system is considered in the numerical section.