Aims: To perform a systematic review to assess and compare the efficacy and safety of all urethral bulking agents (UBAs) available for the treatment of stress urinary incontinence (SUI) in women.Methods: This systematic review was conducted in accordance with the PRISMA guideline. A systematic search was conducted using the Ovid Medline, Embase and PubMed databases. Studies were included if they involved women who underwent either Bulkamid®, Macroplastique®, Durasphere®, Coaptite®, or Urolastic® injections for the treatment of SUI. A total of 583 articles were screened with 56 articles included. A qualitative analysis was performed.Results: The newer synthetic UBAs are not inferior to Contigen®, with variable mean success rates of 30%-80% in the short-term. Better long-term success rates were found with Bulkamid® (42%-70%), Coaptite® (60%-75%), and Macroplastique® (21%-80%) on qualitative review. Urinary tract infection rates were similar between bulking agents (4%-10.6%) although temporary acute urinary retention was more commonly associated with Coaptite® (mean: 34.2%), and de novo urgency in Durasphere® (mean: 24.7%). Significant complications such as migration into lymph nodes was reported with Dura-sphere®. Erosion was reported with Macroplastique®, Coaptite®, and Urolastic®, with a rate as high as 24.6% in one study of Urolastic®. Conclusion: Available data support the use of Bulkamid® and Macro-plastique®, which has shown a short-term efficacy of 30%-90% and 40%-85% respectively, and long-term efficacy of 42%-70%, and 21%-80%, respectively. Bulkamid® appears to have a more favorable safety profile, with no cases of erosion or migration of product associated with its use. Direct comparisons of UBAs have not been performed.