In this paper, an H.264 encoder is proposed which incorporates a noise pre-filter with little additional complexity. The motion estimation process in the H.264 encoder, applied to multiple reference pictures, is re-used for temporal noise filtering. Significant objective and subjective improvement is observed for the proposed system versus a standalone H.264 encoder, with greater improvement at higher bitrates. For sequences with artificially generated noise, average PSNR improvements of 0.46 to 1.96 dB were obtained. The optimum number and type of pictures to use in the temporal noise filter was also studied. The proposed single stage encoder with noise filter system provides only a slight reduction in performance as compared to a more computationally complex two-stage system with separate noise filter and encoder.