Objective To evaluate the feasibility,safety and accuracy of endoscopic ultrasonography guided fine-needle aspiration(EUS-FNA) in patients with mediastinal benign and malignant lesions.Methods A linear array scanning endosonography (Pentax-EG3630U) and a 22-guage (Wilson-CooK) needle were used to perform EUS-FNA in 22 patients with mediastinal lesions.Results EUS-FNA revealed 15 patients with carcinoma and 6 cases with benign tumors,which were confirmed by mediastinoscopy.One patient was not diagnosed because of inadequate specimen.None of the patients had complications caused by any procedures.Conclusion EUS-FNA is safe,reliable and accurate in diagnosis of mediastinal benign and malignant lesions.