Abstract: An improved optical fluorescence optical imaging system is disclosed having an excitation radiation source and an emission imaging camera. The imaging system is designed for capturing video fluorescence emission images of live animal tissue in blood containing fluorescent dye. The excitation radiation source unit can easily be adapted for use with different excitation wavelengths as can the imaging camera. Hence, the system is amenable for use with a variety of different fluorescent dyes, including those with exciting wavelengths in the ultraviolet, visible, and infrared spectral regions. The small size of both the optical excitation radiation source and emission imaging camera make the entire system relatively unobtrusive to surgeons and other health care personnel in a surgical suite.