Light in the near-infrared (NIR) region between 700-900 nm can penetrate deep into living tissue, thereby offering a unique opportunity to use near-infrared fluorescence (NIRF) imaging techniques to detect and visualize fluorescent probes in-vivo. In the past few years, many novel NIR fluorescent probes have been designed, synthesized and studied in a variety of disease conditions. Recent research has focused primarily on the class of cyanines dyes as non-specific agents and as part of specific NIR fluorescent probes. The publications reviewed herein discuss the characteristics of cyanine dyes and their conjugates and present examples for the application of these probes for imaging vascular pathophysiology.