Background: There is increasing evidence to support the use of anesthetics to affect operative fields during endoscopic sinus surgery and thus the speed, thoroughness, and safety of the surgery itself. Previous research has suggested preoperative beta-blockers improve surgical fields (SFs); our study is novel in showing the impact of a beta-blocker infusion on SFs during sinus surgery. Methods: A prospective, randomized, double-blind, placebo-controlled trial was conducted in 40 patients. Patients undergoing endoscopic sinus surgery for chronic rhinosinusitis received a constant infusion of i.v. esmolol or saline in addition to a standard inhaled anesthetic protocol. At regular 15-minutes intervals, the quality of SF, heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were assessed. Total blood loss was also recorded. Results: Average vital sign parameters (HR/SBP/DBP) were significantly lower in the esmolol group (69.1/90.2/55.1 versus 77.2/99.5/63.5; p < 0.01). The esmolol infusion improved SFs relative to control (2.3 versus 2.6; p = 0.045). Esmolol infusion resulted in good SFs (grades 1 and 2) more often than poor fields (grades 3 and 4); on the contrary, the control group showed more poor than good SFs (chi-square; p = 0.04). A correlation between increasing HR and worsening SFs was identified (r = 0.259; p = 0.002). The control group had significantly higher average blood loss (1.3 versus 0.8 mL/min; p = 0.037). Conclusion: Esmolol-induced relative hypotension and bradycardia during endoscopic sinus surgery achieves significantly improved SFs relative to saline control.