When polypropylene meshes are used in reconstructive urogynecological surgery, the erosion rates vary from 3.3% to 14% and causative factors for such erosions are still unknown in many cases. Therefore, the aim of our study was to establish the role of immunologic factors in the process of polypropylene tapes erosions after suburethral sling procedures. Serum concentrations of tumor necrosis factor alpha, interleukin (IL)-2, IL-4, IL-5, IL-10, and interferon (IFN)-gamma were estimated in 123 patients suffering from stress urinary incontinence preoperatively and during 12 months follow-up using Human Th1/Th2 Cytokine Cytometric Bead Array I kit. The same immunological assessment was performed in each case of detected tape erosion. Statistical calculation was performed using UNIVARIATE, CORR, and NPAR1WAY procedures from Statistical Analysis System. The unpaired Student's t test, nonparametric Mann-Whitney U test, and Wilcoxon tests were used. Preoperative IFN-gamma concentration was significantly higher in women with subsequent polypropylene mesh erosion when compared to women with successful outcome (p < 0.05). Th1 cytokine profile may be related to the risk of the vaginal erosions following placement of polypropylene meshes. The way to lower erosion rate may involve exclusion of the patients immunologically prone to synthetic material erosion. The factor which can help to select such patients could be preoperative level of IFN-gamma.