OBJECTIVE To report the long-term refractive results of photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) in patients with thin corneas. METHODS A long-term, retrospective, non-randomized follow-up study. METHODS Sixty-three patients (124 eyes) (28 males and 35 females), who had a preoperative central corneal thickness (CCT) of less than 500 microns and completed at least one year of follow-up examinations after surgery. Thirty-five patients (68 eyes) underwent PRK and 28 patients (56 eyes) underwent LASIK. RESULTS Mean preoperative corneal pachymetry was 484.95 +/- 6.65 microm (range, 470 to 498 microm) and 482.38 +/- 10.73 microm (range, 453 to 499 microm) for LASIK and PRK, respectively. No intraoperative complications were found in both groups. None of the included eyes developed postrefractive corneal ectasia. The mean predictability for the PRK group was 0.08 diopters (D) with a standard deviation of 0.40 D (range, -1.38 to 1.00 D), and the mean predictability for the LASIK group was 0.14 D with a standard deviation of 0.55 D (range, -1.25 to 1.33 D). CONCLUSIONS Refractive laser surgery with LASIK or PRK in patients with thin corneas (less than 500 microm) seems to be a safe and predictable technique for myopic refractive corrections.