A mathematical simulation method was developed for visualization of the diffuse reflected light on a surface of 3-layered models of urinary bladder wall. Five states, from normal to precancerous, of the urinary bladder epithelium were simulated. With the use of solutions of classical electrodynamics equations, scattering coefficientsμsand asymmetry parametersgof the bladder epithelium were found in order to perform Monte Carlo calculations. The results, compared with the experimental studies, has revealed the influence of the changes in absorption and scattering properties on diffuse-reflectance signal distributions on the surfaces of the modelled media.