A nasally inserted airway opening device with inflatable cuff is provided to treat obstructive sleep apnea. The airway opening device includes a hollow flexible tube extending between a proximal end and a distal end, and an inflatable cuff attached to the tube at or near the distal end. The inflatable cuff may be inflated and deflated via the tube. The inflatable cuff defines an interior through hole extending along the length thereof. When deflated, the inflatable cuff may be packed closely to the tube and may be inserted or removed through a nostril of a user. When inserted through the user's nostril and positioned in the user's oropharynx or naso-oropharynx and inflated, the inflatable cuff prevents soft tissue in the user's naso-oropharynx from collapsing toward the posterior pharyngeal wall while simultaneously allowing airflow through the through hole. A method for utilizing the airway opening device to prevent/treat sleep apnea is also provided.