Although atherothrombotic complications due to ovulation induction are well known in the literature, there is no previous report specifically on the presentation of a lateral medullary infarction. Recently, we have encountered a 36 years old woman with primary infertility having acute vertiginous attack after ovulation induction. Audiovestibular test battery revealed bilateral normal hearing, bilateral gaze nystagmus, rebound nystagmus beating toward the right side, loss of visual suppression with augmentation of caloric nystagmus in light on the left side, and delayed vestibular evoked myogenic potentials on the left side, which was subsequently confirmed as lateral medullary syndrome by MRI scan. In this patient, polycystic ovary syndrome plus high levels of follicle stimulating hormone (FSH) and estrogen, together with S protein deficiency may precipitate the occurrence of lateral medullary infarct after ovulation induction. Thus, in vitro fertilization treatment protocol has been terminated.