Complete surgical resection of all malignant tissue remains the most reliable cure for cancer. To facilitate quantitative removal of all cancer lesions, we have developed low molecular weight ligand-targeted fluorescent dyes that bind to receptors on cancer cells and thereby illuminate tumor tissue without highlighting normal tissue. With the aid of these dyes surgeons have been able to i) find and resect more malignant lesions, ii) detect and remove positive tumor margins, iii) more accurately stage cancer patients, and iv) locate and resect more malignant lymph nodes than was previously possible using standard surgical methods of palpation and visual inspection. In this presentation, Dr. Low will summarize both preclinical and clinical data on the design, synthesis and use of ligand-targeted fluorescent dyes for intra-operative imaging of cancers and various inflammatory diseases. Data will also be presented on new targeting ligands that selectively deliver attached near infrared dyes to tumor stromal cells that have heretofore been difficult to visualize (e.g. tumor fibroblasts, tumor-associated macrophages, MDSCs, T cells, etc.). Finally, mention will also be made of novel near infrared fluorescent imaging agents that allow imaging of ureters and blood vessels at emission wavelengths that are distinct from those used in cancer imaging. Taken together, these new reagents should allow the assembly of a new toolbox of different colored NIR dyes for the imaging of diseased tissues that need to be resected as well as healthy tissues that need to be preserved during fluorescence guided surgery.