Introduction: The etiology of pregnancy-related pubic symphysis pain (PSP) is usually considered as the change in pelvic biomechanics during pregnancy. However, the biomechanical changes that occur during puerperium, and the difference of radiographic dimensions in women with different types of PSP remains unknown. Materials and Methods: Fifty women with self-reported PSP were included. Two conventional X-ray radiographic dimensions obtained on the delivery day and one-month postpartum were compared by using paired t-test. Based on the self-reported VAS at one-month postpartum, variables between pain-recovery and non-recovery groups were also compared. Results: The comparison between pre- and post-values indicates a reduced distance between FLAMs (239.1 vs. 237.0 mm), PS separation (7.9 vs. 6.5 mm), and PS translation (4.1 vs. 3.1 mm). No significant differences were observed in the distance between FLAMs, width of PS separation, or pubic symphysial surface (PSS) angle between the recovery and non-recovery groups. However, the non-recovery group exhibited a significantly large change in PS translation at one-month postpartum than the recovery group (-1.8 vs. -1.1 mm). Conclusions: The pelvic radiography demonstrated a 'closure' alteration in the pelvic cavity diameter onemonth postpartum with a decrease in the distance between FLAMs and shortened PS separation. The difference in radiographic diameters between groups was not clearly evident.