The status of the polymer optical fiber (POF) for high-speed data communication is reviewed. Recently, the low-loss and high-bandwidth perfluorinated GI POF which has no serious absorption loss from visible to near infrared region was successfully prepared at Keio University. Since the core diameter (300–1000 μm) of the GI POF is much larger than that of the multimode silica fiber (62.5 μm), the serious modal noise in the conventional multimode silica fiber was virtually eliminated, resulting in stable giga bit order data transmission with inexpensive couplers and connectors.