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. 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. 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 Durasphere®. Erosion was reported with Macroplastique®, Coaptite®, and Urolastic®, with a rate as high as 24.6% in one study of Urolastic®. Available data support the use of Bulkamid® and Macroplastique®, 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.