The early detection and subsequent prevention of cancer have been a challenging task for researchers all over the world. Some of the conventional techniques used for the diagnosis of cancer are mammography, ultrasonography, magnetic resonance imaging (MRI), positron emission tomography (PET) and histopathology. In recent years, optical imaging is being developed as powerful techniques for the early and quick diagnosis of cancer. This book provides the information about polarimetric techniques and their applications in diagnosis of cancer in biological tissues. Polarization gating and Mueller decomposition imaging technique were addressed in the detail with their applications on cervical tissues and mimic of tissues (tissue phantoms). Polarization gated imaging can be used to detect mature tumors in the superficial layers. However, Mueller decomposition images have shown promising results about dysplasia in human cervical tissues. These images can be used to discriminate normal cervical tissue against the dysplastic (pre-cancerous) tissue. These results can be useful for clinical purposes and in the research work for diagnostic tools