Objective: Chronic rhinosinusitis with nasal polyposis (CRSwNP) is a multifactorial disease in which the sinus and nasal mucosa are affected. We investigated the relationship between the genetic polymorphism of MMP 9 (rs17576) and TIMP 1 (rs48498) and se-rum levels, and we wanted to investigate the effect of MMP 9 and TIMP 1 genotypes on Vitamin serum levels in CRSwNP with and without Aspirin-Exacerbated Respiratory Disease (AERD).Materials and Methods: This study consisted of 99 patients with CRSwNP with AERD and CRSwNP without AERD. The RT-PCR method and ELISA were used in this study. ELISA was used for MMP 9 and TIMP 1 serum levels and Vitamin D levels.Results: Serum levels of MMP 9 were markedly higher in AG genotype than GG genotype in CRSwNP with AERD. Serum levels of MMP 9 were statistically higher in carrying of A (+) allele in CRSwNP with AERD than in not carrying of A (+) allele. In ad-dition, serum levels of Vitamin D were discovered significantly lower in TIMP 1 CT genotype in comparison to CC and TT gen-otypes in all of CRSwNP.Conclusion: The rising of MMP 9 serum levels may be a marker of chronic inflammation or they may be a significant factor in the resistance to diseases. This study may lead to a further under-standing of disease severity in CRSwNP with AERD.