Imaging can be used to develop effective biomarkers to provide information on diseases and assessing therapeutic effects. In the past decade, several imaging modalities have been used for early detection of drug response. Although many imaging techniques are available to the medical community, no single method provides all the necessary information. For instance structural MR and CT imaging modalities provide anatomical information whereas PET and optical imaging can provide functional information. Often, it is useful to combine complementary information from different modalities, through a technique known as image registration. In addition, statistical characterization of morphological differences within and between groups or automated identification and labeling of specific anatomical structures with an atlas requires image registration. Therefore it is essential to understand image registration techniques to enable their effective use in imaging applications. In this talk, I will describe recent advances in image registration and provide examples of how it is being used in medical imaging towards drug discovery and development.