In the last few years, quantitative receptor autoradiography has been extensively employed to study the distribution and the functional role of area-specific transmitter receptors in the central nervous system. In the present paper we have developed quantitative methodologies for the analysis of autoradiograms using computerized image analysers coupled with standard TV camera input for the microdensitometrical evaluations. These procedures include the assessment of the film response to radioactivity using appropriate standards calibrated according to brain tissue quenching and non-linear conversion of density measurements in radioactivity values adopting the best mathematical model fitting to give as little variability as possible in the transformations. The reliability of the proposed approach has also been evaluated by means of a computer-assisted Monte Carlo simulation and parallel biochemical determinations.