Background. The high prevalence of primary dysmenorrhea (PD) among young females has prompted interest in exploring its multifactorial causes. One area of investigation is the relationship between musculoskeletal posture and gynecological health. Purpose. To examine the potential correlation between spinopelvic alignment and uterine dimensions in females with and without PD. Methods. This case-control observational study included 40 females with regular menstrual cycles, divided into two groups: 20 with PD (study group) and 20 without PD (control group). Spinopelvic alignment parameters, including thoracic kyphosis, lumbar lordosis, pelvic tilt, and pelvic torsion, were assessed using a 4D formetric device. Uterine dimensions, including corpus length and width, as well as cervix length and width, were measured by ultrasonography. Results. No significant correlations were found between the spinopelvic alignment and uterine dimensions in the study group with PD (p > 0.05). However, in the control group without PD, there were significant moderate negative correlations between uterine corpus width and thoracic kyphotic angle (p < 0.05), as well as between cervix length and pelvic tilt (p < 0.05). Conclusion. In females with PD, there are no significant correlations between spinopelvic alignment and uterine dimensions. In contrast, in females without dysmenorrhea, there are significant correlations between uterine corpus width and thoracic kyphotic angle, and between cervix length and pelvic tilt.