Stress urinary incontinence (SUI) is a condition of involuntary loss of urine on effort, physical exertion, sneezing, or coughing that is often bothersome to the patient and frequently affects quality of life. When women are evaluated for SUI, counseling about treatment should begin with conservative options. The minimum evaluation before primary midurethral sling surgery in women with symptoms of SUI includes the following six steps: 1) history, 2) urinalysis, 3) physical examination, 4) demonstration of stress incontinence, 5) assessment of urethral mobility, and 6) measurement of postvoid residual urine volume. For women with uncomplicated SUI in whom conservative treatment has failed and who desire midurethral sling surgery, evidence indicates that the performance of preoperative multichannel urodynamic testing versus a basic evaluation does not affect treatment outcomes. However, women who have complicated SUI may benefit from multichannel urodynamic testing and other diagnostic tests before initiation of treatment, especially surgery. Clinical judgment should guide the health care provider's decision to perform preoperative multichannel urodynamic testing or to refer to a specialist with appropriate training and experience in female pelvic medicine and reconstructive surgery.