Torsion of an ovary or fallopian tube (adnexal torsion) usually occurs in ovaries with tumors or functional cysts. In polycystic ovarian syndrome (PCOS), the ovaries are bilaterally enlarged, but these enlarged ovaries rarely twist. Recently, the authors encountered a PCOS patient with ovarian torsion after the cessation of Kaufmann treatment. The etiological factors were unclear, but the authors suggest that the increase in ovarian volume was due to transient hypergonadotropic feedback. Thus, more attention should be paid to adnexal torsion that may arise subsequent to transient hypergonadtropic states, in relation to the cessation of hormonal treatment, and enlarged ovaries in PCOS patients.