AIM: To evaluate the efficacy and safety of corneal collagen crosslinking (CXL) to prevent the progression of post-laser in situ keratomileusis (LASIK) corneal ectasia. METHODS: In a prospective, nonrandomized, single-centre study, CXL was performed in 20 eyes of 11 patients who had LASIK for myopic astigmatism and subsequently developed keratectasia.The procedure included instillation of 0.1% riboflavin-20% dextrane solution 30 minutes before UVA irradiation and every 5 minutes for an additional 30 minutes during irradiation. The eyes were evaluated preoperatively and at 1-, 3-, 6-, and 12-month intervals. The complete ophthalmologic examination comprised uncorrected visual acuity, best spectacle-corrected visual acuity, endothelial cell count, ultrasound pachymetry, corneal topography, and in vivo confocal microscopy. RESULTS: CXL appeared to stabilise or partially reverse the progression of post-LASIK corneal ectasia without apparent complication in our cohort. UCVA and BCVA improvements were statistically significant(P＜0.05) beyond 12 months after surgery (improvement of 0.07 and 0.13 logMAR at 1 year, respectively). Mean baseline flattest meridian keratometry and mean steepest meridian keratometry reduction (improvement of 2.00 and 1.50 diopters(D), respectively) were statistically significant (P＜0.05) at 12 months postoperatively. At 1 year after CXL, mean endothelial cell count did not deteriorate. Mean thinnest cornea pachymetry increased significantly. CONCLUSION: The results of the study showed a long-term stability of post-LASIK corneal ectasia after crosslinking without relevant side effects. It seems to be a safe and promising procedure to stop the progression of post-LASIK keratectasia, thereby avoiding or delaying keratoplasty.