Pelvic floor dysfunction is common to a variety of conditions, the most prevalent of which is stress urinary incontinence (SUI).This condition can have significant impact on physical and psychological health, quality of life, as well as cause increased socioeconomic burden. First-line treatment for SUI typically includes pelvic floor muscle training (PFMT) for at least 3 months. It is unclear if additional treatments could provide the same or more benefits for women with SUI, including biofeedback (BF), electrical stimulation, bladder diaries, and combined home and clinic programs. The combination of PFMT with BF for treatment of SUI has not been evaluated; this study was designed to assess if PFMT with pressure-mediated BF is better than PMFT alone in terms of severity of SUI, rates of cure and improvement, PFM strength, quality of life, self-efficacy, and adherence to therapy in postpartum women after 3 months. This was a multicenter, assessor-blinded parallel-group randomized clinical trial of postpartum patients with new-onset SUI. Inclusion criteria were age 18 or older and new-onset SUI or stress-predominant urinary incontinence within 12 weeks postpartum. Exclusion criteria included urgency urinary incontinence alone, third- or fourth-degree perineal tears, diastasis recti abdominis and chronic pelvic pain, prepregnancy SUI, previous pelvic surgery, history of formal PFMT in the past 5 years, and inability to contract PFMs. The primary outcome was the severity of urinary incontinence as assessed by the International Consultation on Incontinence Questionnaire–Urinary Incontinence Short Form (ICIQ-UI SF). Additional outcomes included cure and improvement of SUI (defined as ICIQ-UI SF score of 0 after 3 months or reduction of 3 or more points compared with baseline), PFM strength, quality of life, self-efficacy, and completion and adherence to PFM training. Final analysis included 452 individuals, with 223 randomized to the intervention group (PFMT and BF) and 229 in the control group (PFMT alone). About 88% of participants delivered vaginally, with 35% experiencing episiotomy and 68% some form of perineal laceration. No significant differences were found between the 2 groups at baseline. Improvements in ICIQ-UI SF scores from baseline to 3 months were significantly greater in the intervention group (P = 0.002), including frequency, amount, and impact of urine leakage on life (P = 0.003, P = 0.02, P = 0.04, respectively). Significant improvement over baseline was shown in the intervention group versus controls in individuals with both mild (P = 0.008) and moderate SUI (P = 0.04), but there were no significant differences between groups in patients with severe SUI. The intervention group had more individuals who were considered cured with ICIQ-UI score of 0 (P = 0.001) or improved (P = 0.002) compared with controls. Additionally, the maximum voluntary contraction pressure measured by blinded assessors was significantly greater in the intervention group than in the control group (P = 0.02). Quality of life was shown to be improved after 3 months of treatment in both groups when compared with baseline, with no significant differences between groups. At 3 months, the control group had significantly lower scores for self-efficacy than the intervention group (P = 0.02), though there were no significant differences at baseline. Lastly, no differences were found between groups in adherence or completion of training regimens. These results indicate that pressure-mediated BF in combination with PFMT was superior to PFMT alone in improving SUI severity, rates of cure and improvement, and PFM strength. Findings were most compelling for women with mild or moderate SUI as measured by ICIQ-UI score. This study adds evidence to show that additional treatments can reduce the healthcare burden and improve outcomes for individuals with SUI, but specific benefits of BF are still under debate for this application. There are several different types of BF, and it has not yet been evaluated which, if any, may have the most benefits. Future research should compare different types of BF and their effect on outcomes for SUI, as well as removing potential confounders and increasing both sample size and diversity