Objective The aim of this retrospective cohort study was to analyze responses to intravenous (IV) phenytoin (PHT) for trigeminal neuralgia (TN) crisis in a group of patients treated at our institution. Background TN is one of the most common causes of facial pain. Its treatment relies on preventive therapy with either carbamazepine or oxcarbazepine. During severe pain episodes, patients may be unable to eat, drink, or even swallow oral medication, requiring in‐hospital treatment. There is scarce evidence to support IV medication use for TN, making management of this condition difficult. Methods We reviewed clinical records of patients with TN crisis consulting the emergency department at a tertiary neurological referral center in Buenos Aires, Argentina, treated with IV PHT as analgesic strategy, and with at least 1‐month posttreatment follow‐up. Demographic features, magnetic resonance imaging findings, and therapeutic management were analyzed. Results Thirty‐nine patients with TN were included, 18 (46.2%) receiving IV PHT more than once (total number of infusions administered, 65). Immediate pain relief was observed in 89.2% (58/65) and 15.4% (10/65) presented side effects. Conclusions We recommend IV PHT as acute rescue treatment in TN crisis.