Aims: The aims of this study were to investigate the clinical effects and safety of botulinum toxin A (BTX-A) in treating trigeminal neuralgia and its influences on accompanied depression, anxiety, sleep disorders, and quality of life. Methods and Material: Eighty-seven patients with one-branch classical trigeminal neuralgia were injected with BTX-A in the pain area. The visual analogic scale score, sleep interference score, Hamilton Anxiety Scale score, Hamilton Depression Scale score, and side effects were assessed at 1 week prior to and 8 weeks after treatment, respectively. Results: The effective rates after 1, 2, 4, and 8 weeks of treatment were 48.28%, 66.67%, 78.16%, and 80.46%, respectively. The effective rates of anxiety and depression were 90.32% and 96.77%, respectively. When compared to that before treatment, the quality of life was significantly better in terms of role-physical, bodily pain, general health, vitality, social functioning, role-emotional, and mental health (all P < 0.01), while physical function was not significantly improved (P = 0.317). Conclusion: BTX-A treatment can significantly relieve the pain in trigeminal neuralgia patients; improve anxiety, depression, and sleep; and increase the quality of life. BTX-A treatment is a safe and effective method to treat classical trigeminal neuralgia.