Background: Trigeminal neuralgia (TN) is a severe neuropathic pain condition in the orofacial region, with carbamazepine recommended as the first-line treatment. Nonetheless, its application is constrained by unfavorable drug responses and side effects. The objective of this research was to assess the effectiveness and safety of lacosamide, a third-generation anticonvulsant, in individuals with TN, and to juxtapose the findings with observational records from recently diagnosed TN patients who underwent carbamazepine monotherapy within the corresponding timeframe. Methods: An 8-week flexible dose titration of lacosamide was performed on newly diagnosed 12 TN patients who were divided into two groups: 200 mg/day (n = 5), and 400 mg/day (n = 7). Outcome measures included average pain score, Brief Pain Inventory-facial scores, and side effects. Patients were followed-up at 2, 4 and 8 weeks after baseline. Results: The percentage change of pain score at 4-week visit was compared between both lacosamide groups and patients receiving carbamazepine (n = 6) for four weeks during concurrent period. Both lacosamide groups experienced a decrease in pain score at 2-week follow-up, and differences in average pain score reduction were not observed between the two groups across all visits (p > 0.05). The mean Brief Pain Inventory-facial score in the lacosamide 200 mg/day group was higher than that in the 400 mg/day group at the 2-week follow-up (p = 0.03). Interestingly, the 4-week follow-up revealed that there were no significant variances in pain intensity between the lacosamide and the contemporaneous carbamazepine cohorts (p > 0.05). Frequently noted adverse events were mild somnolence (n = 9), slight vertigo (n = 5), and emotional lability (n = 2) without instances of severe adverse drug responses. Conclusions: Lacosamide demonstrates potential as a therapeutic option for patients suffering from trigeminal neuralgia. Clinical Trial Registration: TCTR20210811002.