Clinical results obtained endoscopically with an imaging fluorescence photodetection apparatus based on the use of one excitation wavelength and detection of the fluorescence emission performed in two separate spectral windows are presented. Early cancer photodetection of micro-invasive and in situ carcinoma of the bronchial mucosa after intravenous injection of meso-tetrahydroxyphenylchlorin (m-THPC) was performed during sessions involving photodynamic therapy. Preliminary results are also presented in the context of detecting transitional cell carcinoma of the bladder performed by fluorescence imaging photodetection of protoporphyrin IX (PPIX) following topical application of 5-delta aminolevulinic acid (ALA).