Multipurpose unified Monte Carlo (MC) based model is developed for adequate simulation of various aspects of optical/ laser radiation propagation within biological tissues. The modeling is aimed to provide predictive information to optimize clinical/biomedical optical diagnostic systems and improve interpretation of the experimental results in biomedical diagnostics. Complex structure of biological tissues in terms of scattering and absorption is presented on the example of human skin. Validation and verification are performed against the tabulated data, theoretical predictions, and experiments. We demonstrate the use of the model to imitate 2-D polarization-sensitive OCT images with non-planar boundaries of layers in the medium like a human skin. The performances of the model are demonstrated both for conventional and polarization-sensitive OCT modalities.© (2008) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.