A 43-year-old woman had laser in situ keratomileusis (LASIK) using the IntraLase femtosecond laser (IntraLASIK) to create 110 microm flaps. Despite uneventful flap formation, the flaps in both eyes were extremely thin, making it difficult to lift them. The flap in the right eye resembled an epi-LASIK epithelial flap. It was lifted uneventfully. The flap in the left eye was stretched and torn on lifting, and the procedure was therefore postponed. After 6 months, the IntraLASIK surgical procedure was repeated in the left eye using a thicker and smaller flap than in the first procedure. Despite the improvements associated with using an IntraLase femtosecond laser, thinner-than-intended corneal flaps can occur. Early recognition of such a flap can prevent further complications.