Both inferior turbinate hypertrophy and nasal polyp formation entail the enlargement of the nasal mucosa caused by rhinosinusitis, but their macro/microscopic and clinical findings differ markedly. This study aimed at investigating differences in the expressions of erbB1/2 and the tight junction proteins, claudin-1 and tricellulin, in the two tissues. Ten inferior turbinates and ten nasal polyps were collected. The expressions of erbB1/2, claudin-1, and tricellulin were examined by fluorescence immunohistochemistry and by quantitative real-time transcription-polymerase chain reaction (qRT-PCR). The eosinophil count and % of nasal gland area in the mucosa were also measured. The fluorescence intensities in the inferior turbinates were higher for erbB1/2 and lower for claudin-1 than those in the nasal polyps. The results of qRT-PCR were consistent with the immunohistochemical findings for erbB1/2. The quantity of tricellulin mRNA was significantly higher in the inferior turbinates than in the nasal polyps. The % of nasal gland area was significantly higher but the eosinophil count was significantly lower in the inferior turbinate than in the nasal polyp. These results suggest that the underlying pathogenesis of hypertrophic inferior turbinates and nasal polyps is likely to differ with respect to regeneration/proliferation and thus the remodeling process.