The outcome of 64 consecutive argon laser iridotomies was examined retrospectively. The patients were followed for a mean of 18 months. Argon laser iridotomy was shown to be effective in treating chronic angle-closure glaucoma, those patients without field loss faring better than those with field loss: 34% of the latter group eventually required a trabeculectomy. It is suggested that patients be carefully followed-up after iridotomy, particularly those with loss of visual field.