Under the postulation that the double Ruiz procedure could increase the effect of radial keratotomy (RK), RK combined with horizontal and vertical Ruiz procedure was performed in three groups of 22 rabbit eyes. In the group A of six eyes, RK with vertical Ruiz procedure was performed, and eight weeks later horizontal Ruiz procedure was added. In the group B of eight eyes, RK with horizontal Ruiz procedure was performed, and four weeks later vertical Ruiz procedure was added. In the group C of eight eyes, RK with horizontal and vertical Ruiz procedure was performed simultaneously. As a control, in the group D of eight eyes, RK without Ruiz procedure performed. Changes in keratometry for four weeks and eight weeks postoperatively were analyzed. The results were as follows: 1. At eight weeks postoperatively, mean changes in keratometry were 6.434D, 3.663D, 4.030D and 1.585D in groups A, B, C and D, respectively. 2. Mean changes in keratometry of groups A, B and C were significantly higher than that of group D. 3. Mean changes in keratometry of 6.434D in group A was significantly the highest of the three groups in which double Ruiz procedure was performed. For the above results, it was concluded that double Ruiz procedure increased the effect of RK, and the procedure was more effective when the secondary Ruiz procedure was added eight weeks later.