The present invention provides specific nucleic acid sequences for use in the identification, classification and diagnosis of various sub-types of lung cancers. The present invention permits one to accurately classify lung cancers based on their miR expression profile without further manipulation. Using microRNA microarray data generated from over two hundred formalin-fixed paraffin-embedded (FFPE) resection samples, fine needle aspiration (FNA) samples and fine needle biopsy (FNB) samples of primary lung cancer, microRNA expression profiles were identified that differ significantly for various sub-types of lung cancer.