Background Isolated fallopian tube torsion associated with hydrosalpinx is a rare condition in the pediatric population. We present this unusual clinical case study in a sexually inactive girl. Case presentation a12-year-old Caucasian girl presented symptoms of acute abdominal pain. Pelvic ultrasound revealed a normal looking uterus and ovaries and next to left ovary a imaging compatible with hydrosalpinx. She was discharged 48 hours later after clinical monitoring with oral analgesia and normal blood workup. At 3 weeks, she was readmitted for acute abdominal pain. Leukocytosis with left shift and raised C-reactive protein were observed. Her clinical condition worsened, and complication of the preexisting hydrosalpinx was suspected. Exploratory laparoscopy confirmed torsion of the fallopian tube. Left salpingectomy was performed. Histopathologic study confirmed a fallopian tube with hemorrhagic infarct. Conclusion Torsion of the fallopian tube must be considered in the event of acute abdominal pain. Early diagnosis and trying conservative management with a view to preserving fertility in this group of patients are essential.