A 78-year-old female patient suffering from Fuchs endothelial dystrophy had uneventful Descemet stripping automated endothelial keratoplasty (DSAEK) on the right eye. One and a half months postoperatively, she underwent a corneal foreign body trauma and was referred to our clinic, complaining about vision deterioration. Slit-lamp examination revealed a severe and diffuse interface lamellar keratitis between the DSAEK graft and the recipient's cornea without any signs of graft dysfunction. Intensive treatment with local corticosteroids was applied immediately, resulting in prompt improvement of both visual acuity and clinical condition. A new clinical entity, described as interface lamellar keratitis after corneal trauma in a DSAEK patient, is presented. Early diagnosis and appropriate intensive treatment with local corticosteroids are essential to successfully address this uncommon post-DSAEK complication.