Long-standing facial palsy sequelae cause functional, aesthetic, and psychological problems in patients. Botulinum toxin is an effective way to manage them, but no standardized recommendations exist. Through this non-systematic review, we aimed to guide any practitioner willing to master the ins and outs of this activity. We reviewed the existing literature and completed, with our experience as a reference center, different strategies of botulinum toxin injections used in facial palsy patients, including history, physiopathology, facial analysis, dosages, injection sites, and techniques, as well as time intervals between injections. The reader will find all the theorical information needed to best guide injections according to the patient’s complaint, which is the most important information to consider.

(1) Background: Sequels of facial palsy lead to major psychosocial repercussions, disrupting patients’ quality of life (QoL). Botulinum toxin (BoNT) injections can permit us to treat long-standing facial palsy, improving facial symmetry and functional signs including synkinesis and contractures. (2) Methods: The main aim of this study was to assess the evolution of the QoL for patients with long-standing facial palsy before, at 1 month, and at 4 months after BoNT injections by using three questionnaires (HFS-30, FaCE, and HAD). The other goals were to find clinical factors associated with the improvement in the QoL and to assess the HFS-30 questionnaire for patients with unilateral facial palsy (3) Results: Eighty-eight patients were included in this study. There was a statistically significant improvement in QoL at 1 month after injections, assessed using the three questionnaires. This improvement was sustained at 4 months after the injections, with a statistically significant difference for the HFS-30 and FaCE questionnaires. (4) Conclusions: This study showed that the BoNT injections lead to a significant increase in the QoL of patients with unilateral facial palsy. This improvement is sustained 4 months after the injections.