The incidence of ovarian torsion has been reported to be increased during controlled ovarian hyperstimulation. In this report we describe exercise-induced ovarian torsion in an ovary with a persistent cyst, following a failed gonadotrophin-stimulated intra-uterine insemination cycle. This report suggests that the risk of ovarian torsion persists beyond the treatment cycle and that patients should be instructed to refrain from exercise or strenuous activity if regression to normal ovarian size has not been documented. Ovarian torsion should be high in the differential diagnosis in patients experiencing abdominal pain with a history of recent gonadotrophin stimulation.