Background: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a safe procedure for the diagnosis of hilar, mediastinal lymphadenopathy or lesions. Various sized EBUS-TBNA needles are available, namely 25gauge(G), 22G and 21G. Recently a new 19G needle has been introduced. Aim: To compare the diagnostic performance of 21G and 19G needles during EBUS-TBNA. Methods: 70 patients with mediastinal, hilar lymphadenopathy or lesions, without specific diagnosis after initial diagnostic bronchoscopy and conventional TBNA (19G), further investigated with EBUS-TBNA were enrolled. EBUS-TBNA bronchoscopy was performed under conscious sedation with the 21G or the 19G needles. In cases where EBUS-TBNA results were negative for malignancy, a surgical biopsy was performed where appropriate. Final diagnosis was established following the histopathological, cytological examination, surgical and clinical-radiologic findings. Results: 21G group included 35 patients (age 66±9, 56 sampling sites) and 19G group 35 patients(age 63±13, 75 sampling sites). Malignancy was diagnosed in 17 cases in 21G and 23 in 19G group. Sample adequacy rates were 92.8%vs96% in cytology, 75%vs90.6% in histology, with diagnostic accuracy of 77.1% vs 80%(p=0.77) in cytology, 48.6% vs 68.6%(p=0.08) in histology and 79.4% vs 83%(p=0.7) combined, with AUC for the diagnosis of malignancy of 0.76(95%CI:0.6-0.9, p=0.001) and 0.85(95%CI:0.7-0.9, p Conclusion: 19G EBUS-TBNA needle proved to be safe, provided more histological material compared to 21G needle and may increase the diagnostic yield of EBUS bronchoscopy.