Background : Functional endoscopic sinus surgery (FESS) is one of the most frequently performed operative procedures in the head and neck field. It has become a standard therapy for chronic rhinosinusitis (CRS) including nasal polyposis that is refractory to conservative measures. Aim of the work: The aim of the study was to compare the outcome of dissolvable carboxy-methylcellulose (CMC) and vinyl gloved Merocele packing in functional endoscopic sinus surgery (FESS) in adult patients. Patients and methods: This prospective, randomized controlled trial study included 26 consecutive adult patients with a diagnosis of CRS with or without polyposis undergoing bilateral FESS, who admitted to the Otorhinolaryngology Head and Neck Outpatients Clinic, Faculty of Medicine, Zagazig University Hospital during the period from December 2017 to December 2018. Results: There were statistical significance difference between CMC and Merocele after 1st and 2nd weeks of operation but this difference disappeared after 4th and 8th weeks in all items. There was a statistical significance reduction in pain score and bleeding score in CMC at all times. There was no statistical significance correlation between age and pain, bleeding or synechia score in either CMC side versus Merocel nasal side. Conclusion: CMC can be a safe candidate for replacing conventional packing materials after endoscopic sinus surgery (ESS).