The authors conducted a retrospective review of clinical / procedure documentation for consecutive blepharospasm (BEB) and hemifacial spasm (HFS) patients undergoing treatment with onabotulinum toxin A (Botox) in one clinic setting over the past 20 years. They report on the tolerance and long-term safety profiles of Botox treatment among Asian patients with benign essential BEB and HFS. Sample size totalled 105 patients with BEB (n=31) and HFS (n=74), all of whom were Asian. The mean follow-up was 84 (range 12-240) months and the mean number of sessions per patient was 19 (range 1-61). On review of dosage, the Botox dose per session increased significantly in both BEB (16.5 versus 21.6 units, p<0.05) and HFS (22.6 versus 26.9 units, p<0.05) patients after a mean of 18 sessions. However, onset time, effective duration and subjective treatment outcome were similar over time in both conditions. At least one local complication was reported among 26% and 41% of patients with BEB and HFS respectively, with ptosis (32%) being the most frequent. Local complications all self-resolved within six weeks post injection. This review allows clinicians to provide this patient group with a full and clear explanation of the potential tolerance of long-term botulinum toxin use.