A 27-year-old man presented with corneal ectasia in his left eye 4 years after myopic laser in situ keratomileusis (LASIK) and was treated with riboflavin-ultraviolet-A (crosslinking). During the first post-treatment days, diffuse lamellar keratitis (DLK) (stage III) developed. The microbiology culture was negative. After intensive treatment with topical corticosteroids, the DLK resolved during the following 2 weeks. Crosslinking for post-LASIK corneal ectasia may induce DLK. Early diagnosis and appropriate treatment with intensive topical corticosteroids is essential to successfully manage this post-crosslinking complication.