In this report, we describe the case of a 51-year-old female who presented to our emergency department with varicella zoster infection. Her relevant medical history included rheumatoid arthritis which was treated with risankizumab. Intravenous acyclovir therapy was initiated due to concern for disseminated disease as she was experiencing T4 dermatomal involvement and new-onset scalp pain. On day 3 of antiviral therapy, the patient developed a sinus bradycardia of 35 beats/min. This persisted until 3 days after the discontinuation of acyclovir. This is the third reported case of sinus bradycardia potentially linked to acyclovir administration. Thus, clinicians should consider intravenous acyclovir as a possible cause of de novo sinus bradycardia.