In recent years, the incidence of sinonasal inverted papilloma (IP) in a stable population has increased significantly. The aim of the study was to analyze the occurrence of IP between the years 2002-2012 in relation to epidemiological factors in an unalterable area. Moreover, we wanted to start a discussion about the difficulties in determining the inci¬dence of benign lesions that are not included in registers. This retrospective study included a group of 69 patients who were treated in the Department of Otolaryngology, ENT Oncology, Poznań University of Medical Sciences. In 2006, we noticed a sudden change in referrals. We compared two groups of patients who were referred during two differ¬ent time periods: 11 patients (2002-2006) and 58 patients (2007-2012). Despite a marked difference in the number of patients, there were no differences between the groups in tumor location (p>0.05), stage (p=0.16), duration of symp¬toms (p=0.39), place of residence, and smoking (p=0.41). The patient`s age was the only variable that differed significantly between the groups (48.45 vs. 56.93 years; p=0.043569, respectively).