The book responds to an epidemiological, observational, analytical research of cases and controls, to identify variations in the effectiveness of allergen-specific sublingual immunotherapy with mites, in persistent asthmatic patients who attended the Allergology consultation of the Hospital Provincial Clínico "Saturnino Lora" of Santiago de Cuba Province, in the period from January 2022 to 2024. The universe is composed of all patients who attended the outpatient consultation of the Allergology Service and met the established inclusion and exclusion criteria. For the selection of the sample, simple random sampling was used, forming two groups: study and control, with a total of 132 patients participating in the study. The study group used sublingual immunotherapy with mites as part of the treatment, 44 patients, and the control group only used pharmacological treatment, 88 patients. It is concluded that sublingual immunotherapy produces variations that responded to decrease in symptomatology, reduction of visits to medical emergency services, less use of rescue medication.