Lupin, a legume with good nutritional value, is used in food production today, most often in bakery products. In Finland, lupin is a labelled ingredient in very few products. Clinically relevant lupin allergy, even anaphylaxis, often occurs in patients without atopic background or other food allergies, whereas lupin sensitization without clinical relevancy most commonly seems to represent cross reactivity to other legumes. Lupin allergy should be suspected and studied in patients with adverse reactions to food, and patients with allergy to other legumes should be advised about possible lupin allergy, as well.