Background: Allergic rhinitis and bronchial asthma are inflammatory conditions that have increased in prevalence over the past two decades; studies of the inflammatory response in these diseases have determined that T regulatory cells (Treg) have been considered as responsible for allergens tolerance. The expression of CTLA-4 (CD152) in Treg is associated with the functional activity of this population, moreover the expression of 4-1BB (CD137) has a controversial function. Objective: To determine the existence of CTLA-4 and 4-1BB in Treg cells in peripheral blood of patients with rhinitis and/or asthma. Material and method: A comparative cross-sectional study was done with three groups of patients: 20 subjects with allergic rhinitis, 17 subjects with bronchial asthma and 17 subjects with both disorders; 19 healthy subjects conformed the control group. The frequency of Treg (CD4+, FoxP3+ and CD25hight) and the expression of CD152 and CD137 in these cells were assessed by flow cytometry in peripheral blood. Results: We found that the group of subjects with bronchial asthma (p<0.001) and allergic rhinitis bronchial asthma (p<0.001) showed a significantly lower percentage of Treg (CD4+, CD25hight and FoxP3+) in peripheral blood compared to the healthy subjects controls. Only the group of subjects with bronchial asthma showed a significantly higher percentage of CD152+ (p<0.01) and CD137+ (p<0.01) Treg compared to control group.  Conclusions: Subjects with bronchial asthma and bronchial asthma and allergic rhinitis disorders have a deficiency of CD4+, CD25hight and FoxP3+ Treg in peripheral blood; however, subjects with bronchial asthma had a higher frequency of CD152+ and CD137+ Treg cells.