Silica optical fibers commonly are used for diagnostic, endoscopic, and surgical applications in medical industries. Optical fiber coatings play an important role in fiber strength, reliability, and biocompatibility. Three major coatings are commonly used on optical fibers: (1) polymeric coatings, such as UV-cured acrylate, silicone, and polyimide; (2) metallic coatings such as aluminum, indium, tin, and gold; and (3) inorganic coatings such as oxides, carbides, nitrides, and carbon. In the medical industry, polymeric coatings are used widely. Metallic and inorganic coatings on optical fibers can also be used. I describe the strength, fatigue, and biocompatibility of silica fibers with different coatings.