The increasing number of the patients with diabetes who use insulin for treatment makes the study of side effects to the above mentioned medicines important and relevant. Due to the current use of human genetically engineered insulin analogues, complications caused by their use develop less often. We described the case of an allergic reaction to the аctrapid and рrotaphane in a patient with Type 1 Diabetes manifested in the form of chronic, recurrent urticaria and angioedema. Sensitization to the above mentioned insulin preparations was proved clinically and with specific immunoallergological methods. The replacement of insulin preparations caused a stable clinical effect.