Introduction : Chronic sinusitis is a common cause of attending Otorhinolaryngology clinics. Hence in this study diseases with symptoms similar to chronic sinusitis were evaluated in Booali Hospital during 2009 and 2010.

  Methods : In this descriptive-analytical cross-sectional survey, 184 nonrandom patients attending Otorhinolaryngology clinics in Booali Hospital during 2009 and 2010 were evaluated. Patients with underlying diseases and or with previous history of sinus surgery and patients less than 16 years or more than 70 years of age were excluded. For statistical analysis Chi square, t, One way ANOVA, Fisher’s exact tests and SPSS V. 11.5 were used.

  Results : The observed differential diagnoses included: 16.3% allergic rhinitis, 10.9% bacterial rhinitis, 19.6% vasomotor rhinitis, 9.8% medicomentosa rhinitis, 4.3% reflux-induced rhinitis, 15.2% tension headache, 13.6% migraine headache, 2.2% temporomandibular dysfunction, 44.6% nasal anatomical obstruction, 1.1% somatization disorder, and 10.9% olfactory dysfunction.

  Conclusion : According to the findings, it may be concluded that in patients with symptoms similar to chronic sinusitis, the differential diagnoses especially allergic and non-allergic rhinitis should be mentioned.