A pellicle including a water-soluble adhesive and a photomask assembly including the pellicle are provided. A pellicle may include a membrane, a pellicle frame, and a water-soluble adhesive disposed on the pellicle frame. The water-soluble adhesive may be prepared by a mixture including a water-soluble acrylic adhesive material in an amount of about 40% to about 55% by weight of the mixture, water or a solution of water and alcohol in an amount of about 40% to about 55% by weight of the mixture, and an additive in an amount of about 1% to about 5% by weight of the mixture.