Medical personnel are without doubt exposed to many biological and chemical agents (e.g., ionizing radiation, ultraviolet light rays, ultrasound, alkylating agents, anasthetic gases and antineoplastic agents) which are efficient inducers of chromosomal aberrations These chromosomal aberrations play an important role in the prediction of many diseases (e.g., cancer) because they are the result of past exposure to carcinogens and also because they are an intermediate end point in the pathway leading to these diseases. Because these agents are widely used in medical diagnosis and therapy, therefore it is highly recommended the continuous research into the nature and the extent of the genotoxic risk and the biological consequences to such exposures.