Cervical mediastinoscopy (CM) is considered to be the gold standard for evaluating mediastinal lymph nodes. The aim of this study was to determine the diagnostic yield of computed tomography (CT) and CM for detecting enlarged mediastinal lymph nodes in non-malignant pulmonary diseases. We retrospectively investigated the correlation and differentiation between chest CT and CM findings in terms of sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), in 30 patients with granulomatous lung disease diagnosed by CM and isolated enlarged lymph nodes seen on CT scans. Biopsy tissues from the lymph nodes in stations right, 1, 2, 3, 4, and 7, were obtained for pathological examination. The 30 patients comprised 11 men (mean age 47.1 +/- 18.4 years) and 19 women (mean age 44.2 +/- 14.0 years). Radiological examination showed that the diagnostic value of stations 2 and 4 was particularly high. Thus, when CM is used for diagnostic purposes, the small lymph nodes in station 1, obtained by careful dissection of the higher mediastinal region, can be helpful. Generally, there is no absolute consistency between the findings of CM and CT. For this reason, obtaining samples from each station regardless of CT findings is recommended.