A coherent fiber image guide comprised of individual fibers with a core diameter as small as 250 nm is reported. By using optical fibers with a very large difference between the indices of refraction of the core and cladding materials, efficient containment of light inside the core is achieved even for submicron core diameters, without the need for metallization. Images with subwavelength resolution are obtained with such an image guide. ©1998 American Institute of Physics.