In this paper, we propose a novel spatio-temporal approach for blotch detection in old movies. Our method operates in the wavelet transform domain to facilitate the localization of the artifacts. Then, we resort to a multivariate statistical test to detect the blotches at all the resolution levels. Our contribution relies on the fact that the detection accounts for the interscale similarities in a single pass without requiring any coarse-to-fine resolution strategy. Experiments on old movies are performed in order to assess the performances of this novel approach.