Cystic fibrosis (CF) is caused by mutations in the gene encoding the CF transmembrane conductance regulator (CFTR) protein, which has a major role as a chloride (Cl(-)) channel. Although perhaps all functions of CFTR are still not fully characterized, localization studies are necessary to understand the consequences of the more than 1000 mutations thus far identified. Our aim was to determine the histological localization of CFTR on respiratory and colon epithelia of human and murine origin with a panel of several antibodies produced against different CFTR epitopes, using an indirect immunofluorescence method. Our results on human tissues confirm the apical localization of CFTR in ciliated cells of the respiratory mucosa and show that in colon tissue CFTR is observed in both apical and basolateral membranes of epithelial cells from colon crypts. However, poor tissue preservation of colon biopsies after immunohistochemistry (IHC) raises doubts about the latter localization. Contrary to human, mouse colon epithelium (not biopsed) presents good tissue preservation and evidences many cylindrical surface cells with high apical expression of CFTR. For the antibodies' sensitivity, we demonstrate that MATG1061, 24-1, M3A7, and MPCT-1 give good results, allowing the histological localization of CFTR protein of both human and murine origin.