Nasal septum deviation can affect the middle ear aeration-mastoid pneumatization system. The aim of this study was to analyze the correlation between the degree of nasal septum deviation with middle ear aeration and mastoid cavity using CT scan. Conducted retrospectively on nasal septum deviation patients who underwent a CT scan of paranasal sinuses at the central radiology department of UNHAS, Makassar for the period of January 2018 to September 2020. Samples were as many as 48 patients aged >18 years who had diagnosed nasal septum deviation. The degree of nasal septum deviation is divided into mild (15°). The statistical method used was the Spearman correlation test. There was significant correlation between the degree of nasal septum deviation with ipsilateral tympanic membrane retraction with a p value 0,001 and ipsilateral mastoid pneumatization with a p value of 0.03 ( The results of this study indicate that there is significant correlation between the degree of nasal septum deviation with ipsilateral tympanic membrane retraction and ipsilateral mastoid pneumatization. There is a correlation between moderate and severe nasal septum deviation with ipsilateral middle ear effusion, where the deviation degree of the nasal septum is getting increased, then there is a tendency for an increase in ipsilateral middle ear effusion compared to contralateral side. Keywords: Degree of nasal septum deviation, middle ear effusion, tympanic membrane retraction, mastoid pneumatization, CT Scan Abstrak: Deviasi septum nasi dapat mempengaruhi tekanan telinga tengah-sistem pneumatisasi mastoid. Tujuan penelitian ini adalah untuk menganalisis korelasi antara derajat deviasi septum nasi dengan aerasi telinga tengah dan rongga mastoid menggunakan modalitas CT-scan. Dilakukan secara retrospektif pada penderita deviasi septum nasi yang menjalani pemeriksaan CT-scan sinus paranasalis di instalasi radiologi sentral RS UNHAS, Makassar periode Januari 2018 sampai September 2020. Sampel sebanyak 48 orang dengan usia >18 tahun yang didiagnosis deviasi septum nasi. Derajat deviasi septum nasi dibagi menjadi ringan (15°) Metode statistik yang digunakan uji korelasi Spearman. Terdapat korelasi yang bermakna antara derajat deviasi septum nasi dengan retraksi membran timpani ipsilateral 0,001 dan pneumatisasi mastoid ipsilateral 0,03 (Kata kunci: Derajat deviasi septum nasi, efusi telinga tengah, retraksi membran timpani, pneumatisasi mastoid, CT Scan