Background: Adnexal torsion (AT) is among the gynecological emergencies; more common in reproductive age, if diagnosed late, this can cause ovarian failure and infertility, but rarely thrombophlebitis and peritonitis. Despite these severe complications, preoperative diagnostic tests are not enough for early diagnosis. There are certain pieces of literature on the subject that reveal changes in mean platelet volume (MPV) values occur in inflammatory and ischemic diseases and that these changes have diagnostic and prognostic significance. However, there are no studies investigating this relationship with adnexal torsion. Aims: The aim of the study is to investigate the diagnostic and prognostic significance of the mean platelet volume value in the early diagnosis of patients with adnexal torsion.