Between 1992 and 1998 at the Pathology Section, Cytopathology Unit of the Department of Oncological and Surgical Sciences of the University of Padova, we performed one hundred and twelve FNACs of adrenal masses under radiological guidance and seven intraoperative scrape smears; histological follow-up was available in 55 cases. Immediate on-site assessment of smears revealed a satisfactory adequacy rate (92%). With a simple diagnostic tree, we have been able to classify all smears except one as benign or malignant correctly, (accuracy 97.6%), differentiation of primary tumours from metastatic depositions remaining the most difficult task. In our experience FNAC is a safe and accurate tool in the diagnostic characterization of adrenal masses.