Stress urinary incontinence (SUI) is a common type of urinary incontinence in women, affecting large proportion of women. Surgical methods, especially suburethral sling operations are the most important modes of the treatment of SUI. Bulking agents were created as an alternative to conventional surgical methods and may be the first line of therapy in certain patients. Periurethral bulking implies implantation of various biocompatible agents around the urethra in order to improve coaptation of the urethral walls during intra-abdominal pressure elevation. The rates of cure are lower with bulking methods as compared with surgical techniques but are associated with a lower prevalence of postoperative complications. Bovine collagen remains the most frequently injected agent worldwide, with cure rates of 53% at 12 months after procedure. Polyacrylamide hydrogel and silicone micro implants have showed promising results, with about 64% improvement rate at 18 to 24 months after procedure. Application of urethral bulking agents is minimally invasive procedure and is mostly applied outpatiently in local anesthesia. Urethral bulking agents are safe for clinical usage. Bulking agents should not be recommended as a method of final cure because they only lead to short-term improvement
