This paper is concerned with designing a fuzzy robust H∞ filter for a class of continuous-time nonlinear systems via Takagi-Sugeno (T-S) fuzzy affine dynamic models based on piecewise Lyapunov functions. Attention is focused on the analysis and design of an admissible full-order filter such that the filtering error dynamics is stochastically stable and a prescribed H∞ attenuation level is guaranteed. It is assumed that the plant premise variables are not measurable so that the filter implementation with state space partition may not be synchronous with the state trajectories of the plant. Based on piecewise quadratic Lyapunov functions (PQLFs) combined with S-procedure and some matrix inequality linearization techniques, some new results are established for filtering design of the underling continuous-time T-S fuzzy affine systems. An examples is given to illustrate the effectiveness and applicability of the proposed design methods.