Fullerens are a group of compounds accidentally discovered in 1985. Their structure is like a curved icosahedron with carbon atoms at every top. They have 12 pentagonal and a different number of hexagonal rings. In chemical reactions they act like alkenes, because of that they react with electron rich compounds. Fullerens have a large number of derivatives like endohedral, exohedral fullerens and nanotubes, because of that they have many applications, from superconductors to biologicaly useful molecules. In solid form fullerens do not exibit antibacterial activity, but only in a form of fullerene water suspensions. Bacteria show changes in membrane potential and in creation of ATP, because fullerens are strong oxidants of these proteins. The amount of fatty trans acids and cyclopropane fatty acids increases, because that is a bacterial defense mechanism. Fullerens do not perforate the cell nor do they damage the cell membrane. It is considered that the initial solvent, which was used for the preparation of fullerene water suspensions contributes to the antibacterial effect.