Urethral bulking agents are used in the treatment of female stress urinary incontinence in a wide variety of patients. Numerous materials have been approved for use in the USA, each with inherent properties that can affect its efficacy and safety profile, but none with characteristics deemed ideal to be used as an injectable implant. Few comparative studies are available to clearly define superiority of one agent over another. Nevertheless, bulking agents have demonstrated efficacy in appropriately selected and informed patients and do represent a viable option for women who do not want more invasive therapy and who understand efficacy and duration are inferior to other surgical options.