Plant pollens are the most common cause of seasonal allergic disease. The number of patients undergoing treatment for allergies to the pollen of Japanese cedar (major antigens, Cry j 1 and Cry j 2) has increased steadily each year. A rice seed-based edible vaccine has been shown to be effective for treating Japanese cedar pollinosis. Rice seeds containing the major T-cell epitopes derived from cedar pollen allergens were orally administrated to mice before systemic challenge with total pollen protein. Mucosal immune tolerance leading to a reduction of allergen-specific IgE, T-cell proliferative reactions, and histamine were induced, resulting in suppression of allergy-specific symptoms such as sneezing. Oral seed-based peptide immunotherapy offers a safe, simple, and cost-effective alternative to conventional allergen-specific immunotherapy using crude allergen extracts for treating allergic disease. A human version of rice seed-based edible vaccine containing seven T-cell epitopes from the Cry j 1 and Cry j 2 allergens was recently developed and is undergoing safety assessments.