In the regulation on the prevention of risks that may occur after interaction with a biological agent prepared by the Ministry of Labor and Social Security, biological agents are defined as “microorganisms, cell cultures and human endoparasites, including genetically modified ones with consequences such as infection, allergy or poisoning”. Considering the working environment conditions, risks and hazards in the health sector, it is seen that employees are frequently exposed to biological risk factors. It is of great importance to protect the health of employees against the dangers and risks that may arise due to the fact that medical laboratories are in very dangerous business lines, their working hours are long and there is uninterrupted service in these laboratories. According to the Ministry, biological factors are examined in 4 risk groups. In the relevant legislation, the groups are grouped according to their probability of causing infection in humans. Infection and infectious diseases are among the main occupational risks for medical laboratory workers. Workers are exposed to pathogenic agents such as viruses, parasites, fungi, rickettsia, bacterial microorganisms or genetically modified organisms. There are many risky tasks for those working in medical laboratory settings. There are also dangerous situations that can be caused by interactions. Biological factors; It can cause negative results by affecting the body through the respiratory tract, skin/mucosa tract and digestive tract. Centrifugation, vortexing, culture cultivation, sharps, pipette use, contaminated materials, spillage and scattering of infectious materials, etc. in the medical laboratory. On the other hand, unsafe behavior of employees is one of the direct and indirect biological hazards in the working environment. In this review study, the biological risks that the workers in the medical laboratory environment are exposed to due to the methods, techniques and equipment used were investigated.