A 65-year-old woman was referred with postoperative persistent corneal edema and interface fluid superiorly without dislocation of the donor button after Descemet's stripping automated endothelial keratoplasty (DSAEK). Slit lamp examination revealed the presence of fluid in the interface between donor and recipient button at the superior part of the cornea but the diagnosis was uncertain clinically due to significant corneal clouding. Anterior segment optical coherence tomography (AS-OCT) examination revealed donor graft dislocation behind the iris at the superior part of the lenticule. This case report demonstrates that donor graft partial dislocation behind the iris after DSAEK could be a potential cause of DSAEK failure. AS-OCT is a useful and noninvasive instrument for detecting the post-DSAEK complication especially in patients in which diagnosis is difficult due to significant corneal clouding.