Rapeseed oil, derived from Brassica napus, is commonly used in both machinery lubrication and European cuisine. This study investigates a potential food allergy linked to rapeseed oil. A 21-year-old patient experienced cervical angioedema after consuming foods containing rapeseed oil. Skin prick tests, SDS-PAGE, and Western blot analyses were conducted, separating water-soluble and fat-soluble proteins of rapeseed seeds. Positive skin prick tests confirmed sensitivity, and a prick-to-prick test with rapeseed oil caused urticaria. Two distinct protein bands (37 kDa and 70 kDa) were identified in the lipid fraction, suggesting unique allergenic properties not previously documented. The patient’s allergic reactions were specifically linked to rapeseed oil, emphasizing the need for further allergen characterization to improve food allergy diagnosis and management.