Objective. To study some clinical, paraclinical and evolutionary aspects of acute allergic reactions. Materials and methods. There were retrospectively studied 84 medical records of patients diagnosed with acute allergic reactions who were in treatment in the departments: therapy, pneumology and gastroenterology of MCH „Sf. Arh. Mihail”, Chisinău, during the years of 2012-2016, with average age 43,7±3,24 years (19-75), men-24 (28,57%), women-60 (71,43%). Hereditary and allergic anamnesis, clinical and paraclinical data (haemoleucogram, Ig-E, ALAT, ASAT, glycemia, cholesterol, creatinine, urea, ECG, pulmonary radiography) were analyzed. The obtained results were subjected to the statistical analysis using the t-student criteria. Results. The study of the hereditary history highlighted the compromised heredity in 30 patients (35,71%), the aggravated allergy hystory-in 10 (11,9%), food etiology- in 30 (35,71%), drug etiology-in 20 (23,8%), cosmetics-in 6 (7,14%), insect bitein 9 (10,71%), unidentified etiology-in 19 (22,61%) patients. Clinical manifestations: urticaria –in 59 (70,23%), Quincke edema – in 2 (2,38%), bronchospasm-in 4 (4,76%); previous antecedents: chronic pancreatitis- in 68 (80,03%), viral hepatitis with a minimum activity- in 12 (14,29%), gastroduodenitisin 4 (4,76%) patients. Biological samples: leukocytosis-in 39 (46,42%) patients, eosinophilia-in 6 (7,14%), elevated ESR-in 35 (41,67%), positive Ig-E-in 14 (16,67%) patients. Complex treatment with glucocorticosteroids, antihistaminic drugs, active charcoal, evacuated clusters improved the condition of patients at 2-3 days with complete disappearance of clinical signs on 5-7 days. Conclusions. 1. Acute allergies occur more frequently in women. 2. Complicated heredity and food factors are at increased risk for acute allergic reactions, which are more common in urticaria.