We report an iatrogenic corneal ectasia that developed after laser in situ keratomileusis (LASIK) in a case of forme fruste keratoconus. One month postoperatively, corneal topography revealed a central steep area that showed rapid progression. Visual acuity in the eye decreased from 20/20 to 20/80. Corneas with forme fruste keratoconus may have altered biomechanical properties compared with normal corneas. Forme fruste keratoconus may be a contraindication for LASIK.