Cytidin-5'-diphosphocholine (CDP-choline) has been shown to improve visual acuity (VA), Contrast Sensitivity and Visual Evoked Responses at least temporarily, in amblyopic patients beyond the plastic period of the visual system. In this paper results are presented of a study conducted on forty-five patients with amblyopia in one eye, aged 5-9 years and followed for one year. Of them, 15 (Group A) were treated with CDP-choline (500 mg daily for 10 days every six months); 15 (Group B) were treated with CDP-choline plus one hour of occlusion daily; 15 (Group C) were treated with one hour of occlusion daily. The final VA values were statistically different from the initial ones, for all three groups. Eleven of the Group A patients showed an improvement in VA after the first treatment; a gradual deterioration took place in 6 patients at the end of the fourth month; VA further improved in 9 patients after the second treatment. At the end of the year, VA was higher than at the beginning in 12 of the 15 patients. Group B had an improvement of VA in 13 patients, starting 10 days from the beginning of treatment. This improvement continued throughout the observation period. Group C had an improvement after one month, which continued for 8 months, without deteriorating. In conclusion CDP-choline enhances the effect of part-time occlusion. CDP-choline could be employed also in younger patients. Longer observation periods are still needed and better means of administration have to be found.