Fine needle aspirations biopsies, CT-guided and endobronchial ultrasound-guided, as a mode of diagnosing and/or staging lung carcinoma, are becoming more frequent. Also, there is greater necessity for classification of lung cancers into subcategories of squamous cell carcinoma and adenocarcinoma for appropriate management. Cytomorphology, based on smears alone, allows this classification in many instances. The aim of the current study was to explore the potential of cell blocks to increase the specificity of diagnosis. The morphological characteristics of sixty-two lung carcinomas were examined. Less well-differentiated squamous cell carcinomas were more readily classified as such on cell blocks. Likewise, cell block sections with architectural patterns including strips of cells, papillae and nests of cells correlated with bronchioalveolar, papillary and acinar/mixed subtypes of adenocarcinoma on follow-up histology. In conclusion, cell blocks provide additional morphological clues and material for ancillary studies for classification of lung carcinomas. Diagn. Cytopathol. 2010. © 2010 Wiley-Liss, Inc.