The invention concerns a method for locating at least one fluorophore or at least one absorber in a diffusing medium, using at least one excitation radiation and at least one fluorescence detector (Φfluo), comprising:a) for at least one pair (radiation source-detector), at least one excitation by the radiation source, and at least one detection of the fluorescence signal emitted by the fluorophore after this excitation,b) identification of meshing of the volume into mesh elements,c) estimation of the location of the fluorophore or absorber in its diffusing medium, by computing a function (Pm) of at least one of three parameters.