BACKGROUND Ovarian torsion is a rare surgical emergency in premenarchal girls. Early diagnosis and surgical detorsion are required to restore blood flow and limit tissue damage. CASE REPORT Here, we present a case of ovarian torsion and appendicitis in an 11-year-old premenarchal girl who presented to our emergency room with a 4-day history of right iliac fossa pain, limping, and fever. Upon initial evaluation in our hospital, her vital signs were stable and clinical examination revealed abdominal guarding and right lower quadrant rebound tenderness with positive Rovsing's sign. Abdominal ultrasound and computed tomography scans showed adnexal cysts and torsion, an inflamed appendix, and free fluid in the abdomen. Intraoperative findings included a twisted gangrenous ovary and an edematous appendix. The patient underwent emergency laparoscopic oophorectomy and appendectomy. CONCLUSIONS This case demonstrates that reactive appendicitis can occur secondary to inflammation of adjacent structures such as the ovary.