Ovarian torsion, although a rare gynecologic emergency, is a threat to women of all ages. Traditionally, ultrasonography and laparoscopy facilitated early diagnosis and treatment of this condition. This case report highlights the usefulness of color Doppler ultrasonography in the diagnosis of ovarian torsion.A 25-year-old patient who conceived after ovulation induction was treated conservatively for mild ovarian hyperstimulation and threatened abortion. She subsequently underwent selective first-trimester multifetal reduction and was admitted and treated for suspected pelvic infection. On the 17th post-procedure morning, ovarian torsion was diagnosed using color Doppler ultrasonography.Because gynecologists face serious management dilemmas when confronted with ovarian torsion, this technique of using color Doppler ultrasonography should provide a highly specific finding in complete ovarian torsion, aiding the clinician in prompt diagnosis and treatment.