In order to investigate the therapeutic effects of undercorrection following radial keratotomy (RK) and photorefractive keratectomy (PRK) for correction of high myopia by excimer laser in situ keratomileusis (LASIK), LASIK was performed on 32 eyes of 16 patients undergoing RK 2 years ago and 38 eyes of 20 patients undergoing PRK 1 year ago. The postoperative uncorrected visual was better than or equal to the preoperative spectacle corrected visual acuity in 49 of 70 eyes (70. 00 %) and achieved the best status of refraction in 64 of 70 (91.43 0%). The best postoperatively corrected visual in all operated eyes were equal to their preoperative ones respectively or just lost 1 line. No severe complication occurred during and after operation. It was suggested that LASIK was a better method for treatment of undercorrection following RK and PRK.