Ultra-high-strength polyethylene (UHSPE) fibers were treated with a pulsed XeCl (308 nm) UV excimer laser to improve their adhesion to epoxy resin, The effects of the number of laser pulses and the treatment environment were explored. The chemical and topographical changes of the fiber surfaces were characterized using X-ray photoelectron spectroscopy (XPS), dynamic wettability measurements, acid scanning electron microscopy (SEM) techniques. The effects of the UV excimer laser treatment on the fiber/matrix interfacial shear strength (IFSS) were evaluated by the single-fiber pull-out test. The XPS data indicated the incorporation of both oxygen and nitrogen on the fiber surface. The wettability data showed that the fiber surface becomes much more polar, as a result of oxygen and nitrogen incorporation, after the laser treatment. The SEM photomicrographs showed increased surface roughness after the laser exposure. All these factors contribute to increase the UHSPE fiber/epoxy resin IFSS by 200-400%.