This paper investigates the robustness of the wavelet transform, implemented by means of the Lifting Scheme (LS), with respect to numerical errors in the representation and calculation of transformed coefficients. The study promises to offer important contributions for the understanding of the LS capabilities when specific implementations are considered. This is a topic of growing interest in these days when the new standard JPEG 2000, based on the wavelet transform, is being finalized. Taking into account the effect of finite precision representation can drive both software and hardware implementations with optimized trade off between complexity and performance; moreover the robustness to numerical errors could be an important feature, not usually considered, in order to select the best wavelet filters.