Adnexal torsion is an uncommon cause of acute abdomen in pregnancy and isolated fallopian tube twisting accounts for a very small number of these cases. These conditions, either in pregnancy or in non-gestational circumstances, are known to be due to both genital and non-genital causes and, in most cases, predisposing factors can be identified. We reviewed the literature and retrieved only 19 cases of isolated fallopian tube torsion in pregnancy treated surgically from 1936 to today, including one recently published case from our experience. The clinical presentation was lower quadrant abdominal pain in all cases. The right side was involved in 90% of the cases. Tenderness was usually present but peritoneal irritation with guarding or rebound was exceptional. Symptoms were nausea and vomiting, scanty vaginal bleeding and dysuria. Signs suggestive of necrosis such as leucocytosis, increased CRP and mild hyperpyrexia were uncommon. Preoperative ultrasound evaluation was performed in eight patients and in all cases an adnexal cyst was detected on the ipsilateral side of the abdominal pain. The case we recently published was carefully investigated preoperatively by Doppler flow ultrasound techniques which allowed for a precise differential diagnosis with total adnexal torsion. This aspect has never been previously considered. The surgical approach showed acute isolated fallopian tube torsion in all the cases and a predisposing factor was identified in 75% of the patients. Foetal and maternal outcome were always excellent. In cases of acute abdomen in pregnancy, with detailed Doppler flow ultrasound evidence of normal ovaries and of a pelvic cyst, an isolated tubal-paratubal cyst torsion should be considered and appropriate ovary-sparing surgical treatment foreseen.