Common variable immunodeficiency (CVID) is a heterogeneous group of disorders, characterized by severe reduction in serum IgG and IgA with normal or low number of B-cells. Interleukin (IL)-4 and IL-10 levels could be altered in CVID patients, while cytokine production could be affected with polymorphisms of gene promoter regions. The allele and genotype frequencies of IL-4 and IL-10 gene promoter polymorphic sites were investigated in 30 CVID patients in comparison with controls. IL-10 GA genotype was the most frequent genotype at position -1082 in CVID patients, whereas IL-10 AA genotype was significantly decreased in the patient group at the same position. For IL-4, TG (-1098) and TC (-33) genotypes were significantly overrepresented in CVID group, while frequencies of IL-4 TT (-1098) and CC (-33) were significantly decreased in the patient group. Frequency of IL-10 ACA and IL4 GCC haplotypes in CVID patients were significantly higher than controls, whilst frequency of IL-10 ACC and IL-4 TCC significantly decreased in the patient group. Considering low frequency of IL-10 ACC low producing haplotype, high production of IL-10 could be explained in CVID patients. High production of IL-4 could also be expected based on haplotypes frequencies of this cytokine gene polymorphisms.