Although visual field defects are common disorders in stroke patients, rehabilitation treatments have developed slowly. In this study, we report a case of a 35-year-old man with quadranopsia and visual agnosia due to right occipital hemorrhage. He had no upper limb motor impairments and began to work as a dental mechanic one month after the stroke, but had to retire because of difficulty in making dental implants. He failed to find things in his lower left visual field, and could not perceive fine differences in slope and depth. He was admitted 2 months after the onset and received occupational therapy for visual agnosia, and treatment for quadranopsia one month after admission. The treatment for quadranopsia was performed using a newly designed computerized visual field training machine consisting of a personal computer system which displayed a fixing point for the eyes at the center of the computer display, and a visual stimulation point at areas between residual vision and quadranopsia on the computer display accompanied by a response warning sound after the patient indicated using a switch when he found the visual stimulation. The visual stimulations contained 20% placebo (no visual stimulation). The computer also calculated the percent of correct responses. After one month of continuous occupational therapy only, his visual agnosia improved but his quadranopsia did not. However, his quadranopsia did improve after repetitive visual stimulation using the computerized visual field training machine. In conclusion, quadranopsia might be improved by repetitive visual stimulation.