ProSeal™ laryngeal mask airway (PLMA) was developed to be more effective especially with glottic airway sealing and is suppose to be an improved device over the classic laryngeal mask airway (cLMA). The PLMA's cuff is bulkier, softer, and more pliable than the cLMA. We reviewed a case were a patient had hand surgery under general anesthesia using the PLMA. After having the hand surgery, the patient suffered from dyspnea and had difficulty with their respirations at a supine position. The problems with dyspnea and respiration after surgery resulted because of difficulties from inserting PLMA No.5 into the patient. We suspect from this case that the problems in dyspnea and respiration were due to the folded cuff and incomplete placement of the PLMA, which resulted in lacerations of the mucosa in the soft palate of the patient. In this paper, we considered the probable causes for lacerations of the mucosa in the soft palate and reviewed all of the relevant literature, especially about the proper placement of the PLMA.