The article analyzes the modern directions of biomedical applications of bismuth nanoparticles. The works demonstrating the use of bismuth nanoparticles as a contrast agent for visualization, as an agent for phototherapy, and as a basis for antibacterial drugs are considered. Emphasis is placed on the theranostic applications of this new material, which are extremely important for the problems of early diagnosis and minimally invasive localized treatment of cancer. Bismuth is considered as a radionuclide for nuclear medicine. Such important questions as biocompatibility, toxicity, and excretion from the body are raised. [ABSTRACT FROM AUTHOR]