Cell is a morphologically and functionally the tiniest living organism, present from the very beginning of life on the Earth. Specialized cell types make up specific tissues and organs of the human body. Cell itself and cell elements are liable to morphological, functional, phenotypic and genotypic alterations in various physiological and pathological states. These alterations are studied by cytodiagnosis to diagnose the disease at cellular level. Cytologic examinations belong to the group of morphological, non-aggressive or minimally invasive tests that are easy to perform for both the patient and the professional. In addition, these tests are highly reliable and preferred to the related diagnostic procedures for providing immediate orientation and definitive diagnosis, thus saving both time and money. With the introduction of adjunctive technologies such as cell-surface marker analysis, computer image analysis, molecular and cytogenetic technologies performed on cytologic smears, cytology has become an ever more important factor in the diagnosis, subtyping and prognosis of malignant tumors. Thorough knowledge of cell morphology is a basis for proper performance and understanding of cytology techniques. A cytologist needs to be familiar with clinical manifestations of the disease and to be informed on all relevant data on the patient and his current and previous medical history, in order to be able to issue findings that are understandable and usable to all clinicians and patients. It requires close collaboration between the cytology laboratory and the ward, and among the cytologist, the patient and the clinician. Good collaboration with other diagnostic professions such as pathology, laboratory, molecular and cytogenetic diagnosis is by no means less important. Cytology as a profession implies knowledge of the morphological characteristics of normal cells and cells in various physiologic states, along with due knowledge of the morphology, phenotypic and genetic features of pathologic alterations. However, synchronizing and combining cytologic morphology with other sophisticated diagnostic procedures to reach an accurate diagnosis, subtyping and prognosis of tumor disease is artistry indeed.