Purpose. The literature indicates that normal healthy women can increase the strength of the pelvic floor muscles (PFMs) by simultaneously contracting the transverse abdominus (TrA) muscle. This study investigated the relationship of the PFMs and the TrA in women with stress urinary incontinence (SUI). Subjects. 15 women with SUI, verified by scores on the Questionnaire of Urinary Incontinence Diagnosis (QUID), were randomly assigned, blocked by age, into 2 exercise groups. The 6 women in the PFM only group had a mean age of 63 years and the 9 women in the PFM+TrA group had a mean age of 49 years. Method. For 2 weeks, all women were trained by rehabilitative ultrasound imaging (RUSI) to correctly contract the TrA or relax the TrA during a PFM contraction depending upon the group assignment. Each woman was examined using the PERFECT scheme and prescribed a patient-specific PFM exercise program. The exercise protocols required 6 weeks of supervised patient specific exercises. Data collection occurred at 3 time periods (before intervention, after intervention, and follow-up) and included: measurement of TrA thickness changes and PFM lift by RUSI, PFM strength and endurance with pressure perineometry, number of incontinence episodes and pad use from bladder diaries, and quality of life (QOL) measurements using the Incontinence Impact Questionnaire (IIQ) and the Patient Specific Functional Scale (PSFS). Results. MANOVA identified no significant difference after interventions between groups. All women significantly improved in PFM strength (P<.001), lift (P=.01), number of incontinence episodes (P<.001), pad use ( P=.02), and QOL measurements (P=.00) from before to after intervention periods. PFM endurance did not change significantly over time for either group (P=.08). There was a greater change in TrA thickness in the PFM+TrA group. Conclusion. PFM exercises done in isolation or with recruitment of the TrA increased PFM strength, endurance, lift and decreased incontinence in women with SUI. Recommendations. Women with SUI can benefit from physical therapists prescribing PFM exercises in isolation or in combination with TrA contractions.