The study compared the values of elastographic score (ES) and strain ratio (SR) in transperineal elastography in women with stress urinary incontinence (SUI) and a control group. The elastographic examination was performed by a single experienced gynecologist on the puborectalis part of the m. levator ani, where ES was rated on a four-point scale (1 = soft, 4 = hard) and SR calculated as the ratio of reference tissue to muscle tension (SR = B/A). Women with SUI had a significantly higher number of vaginal deliveries (2.4 ± 1.3 vs. 1.3 ± 0.9, p = 0.001). At rest, ES values were lower in the SUI group (1.9 ± 0.8 vs. 2.5 ± 0.8, p = 0.002) and SR lower (1.72 ± 0.43 vs. 2.15 ± 0.47, p = 0.001). During the Valsalva maneuver, ES was lower in the SUI group (2.6 ± 0.6 vs. 3.2 ± 0.5, p = 0.001) and SR was lower (2.94 ± 0.53 vs. 3.79 ± 0.61, p = 0.001). Transperineal elastography has demonstrated reduced elasticity of the levator muscle even in women with SUI and may serve as a noninvasive tool to assess pelvic floor muscles.