All practicable applications of fine-needle aspiration cytology (FNAC) for palpable tumors or non-palpable lesions guided with endoscopic and imaging procedures are presented. Multidisciplinary procedures and the technical and biological aspects of FNAC are presented. Indications and diagnostic challenges of FNAC on selected organs and neoplasms are discussed based on personal experience and the literature. Skilled and well-trained cytopathologists, the quality of the aspirate and the cytological preparation as well as supplementary immunocytochemical and molecular genetic analyses are mandatory for reliable diagnostic results. The indications and advantages of liquid-based techniques are discussed.