Polycyclic aromatic hydrocarbons (PAH) represent a group of ubiquitous environmental pollutants. Their toxic effects are demonstrated mainly in tissues with high proliferation. The direct distribution of PAH in non-metabolized form to bone marrow and their biotransformation at this site to the toxic metabolites is necessary for demonstration of their toxic effect here. CYP1B1 that is constitutive expressed by stromal cells plays probably the main role in biotransformation of PAH in bone marrow. Reactions of toxic metabolites, development of oxidative stress and interference with intracellular calcium are ranged between the most important mechanisms of structural and functional changes of bone marrow after exposure to PAH. Pathological induction of apoptosis and malignant transformation of stem cells represent the concrete forms of bone marrow damage, caused by exposure to PAH. The bone marrow constitutes the central organ of hematopoiesis and the sites of production of cells of immune system. Its damage can bring therefore crucial health consequences for the whole organism.