This article studies the problem of nonfragile filtering for delayed nonlinear systems, which are represented by Takagi‐Sugeno (T‐S) affine‐fuzzy model. By employing a reciprocally convex matrix inequality, auxiliary function‐based summation inequalities, S‐procedure, and some decoupled techniques, an improved fuzzy filter design method is proposed. In the design process, uncertainties in filter gains are taken into account, making a contribution to enhancing the robustness of the designed fuzzy filter. This is the first study to propose a nonfragile H∞ filtering method for T‐S affine‐fuzzy systems with time delays. The obtained results enrich the theoretical research of nonlinear systems and provide theoretical guidance for practical applications. Three examples are given to reveal the merits and applicability of the new design techniques.