Pelvic floor hypertonicity and narrowing of the levator ani hiatus is traditionally assumed in women with dyspareunia and considered a therapeutical target by physical therapists. However, accurate pre-treatment assessment of pelvic floor muscles is difficult to perform in clinical sites. In addition, the abdominal musculature has not been evaluated in this population, despite its relationship with pelvic floor disfunctions. The purpose of this study was to determine the existence of differences in the length of the anteroposterior diameter of the levator ani hiatus (APDH), the thickness of the abdominal wall musculature and the interrecti distance (IRD) in subjects with dyspareunia compared to a control group. A cross-sectional observational study was designed using ultrasound imaging to measure the APH, the thickness of the abdominal musculature—rectus abdominis (RA), transverse abdominis (TrAb), internal oblique (IO), external oblique (EO)—and IRD at rest and during contraction. Thirty-two women were recruited through advertising and social webs and divided into two groups: dyspareunia (n = 16) and no dyspareunia (n = 16). There were no statistically significant differences (p < 0.05) in RA, TrAb, OI and OE muscle thickness. No differences in APH or in supraumbilical and infraumbilical IRD were found. The findings of this study suggest that the relationship between the abdominal structure/levator ani hypertonia and dyspareunia remains uncertain.