Polarimetric imaging is gaining acceptance in diagnostic imaging in the wake of its ability to elucidate the structural, compositional, and morphological information in tissues, facilitating its use as a potential diagnostic tool in tissue imaging. The effects of the microstructural tissue changes get reflected in the tissue Mueller matrix, which governs the transformation of the polarization state of the light interacting with the tissue. Thus, by deriving the Mueller matrix, the polarization-dependent behavior of the tissue can be optically characterized. The work in this study focuses on developing an optical polarimetry system for tissue assessment during intra-operative procedures. Experimental investigations have been carried out in the development and calibration of a Mueller polarimetry system in the free space optics configuration. Optical tissue-mimicking phantoms and thin and thick tissue samples were studied using the system. A comprehensive analysis of the derived tissue polarimetric information and its correlation with biological information, that forms the basis for effective tissue discrimination is carried out. An automated Mueller polarimetry system was further developed to investigate thin and thick tissue sections of the colon and breast. This forms the basis for realizing a fiber-based system that can be used during intra-operative procedures. Such an optical biopsy system could aid the physician in examining tissues and localizing tissue margins to decide the sampling areas for biopsy and to decide the extent of tissue excision during a surgery.