Objective: Assess paranasal sinus distribution of topical solutions following endoscopic sinus surgery (ESS) using various delivery devices. Study design: Experimental prospective study. Subjects and methods: Ten cadaver sinus systems were irrigated with Gastroview before surgery, after ESS, and after medial maxillectomy. Delivery was via pressurized spray (NasaMist), neti pot (NasaFlo), and squeeze bottle (Sinus Rinse). Scans were performed before and after each delivery with a portable CT machine (Xoran xCAT), and blinded assessments were made for distribution to individual sinuses. Results: Total sinus distribution was greater post-ESS (P < 0.001). Additional distribution was gained with medial maxillectomy (P = 0.02). Influence of delivery device on distribution was significantly higher with neti pot > squeeze bottle > pressurized spray (P < 0.001). Frontal sinus penetration was greatest after surgery (P = 0.001). Conclusion: ESS greatly enhances the delivery of nasal solutions, regardless of delivery device. Pressurized spray solutions in un-operated sinuses provide little more than nasal cavity distribution. Use of squeeze bottle/neti pot post-ESS offers a greatly enhanced ability to deliver solutions to the paranasal sinuses.