Fluorescent polymeric materials such as hydrogels and particles have been attracting attention in many biomedical applications including bio-imaging, optical sensing, tissue engineering, due to their good biocompatibility, biodegradability, and advanced optical property. This review article aims at summarizing recent progress in fluorescent hydrogels and particles based on natural polymers or natural-synthetic hybrid polymers as the building blocks with a concentration on their bio-imaging-related applications. The challenges and future perspectives for the development of natural or natural-synthetic hybrid polymer-based fluorescent hydrogels and particles are also presented.