As the basic element of life on Earth, carbon boasts a greater diversity of compounds than any other chemical element. Even elementary carbon occurs in several structural forms, including diamonds, graphite, fullerenes and carbon nanotubes (CNTs). The latter are well known and promising nanomaterials. CNTs have exceptional properties, combining high resistance, tensile strength and electrical conductivity with a very low weight. Carbon nanotubes are produced in numerous industries worldwide, with CVD (chemical vapour deposition) currently being the most relevant processing technology. CNTs are used as additives to various plastics in electronics, car manufacturing and shipbuilding or for the production of sports equipment. In the future, CNTs are expected to be used particularly in environmental and energy engineering, possible applications including enhanced batteries, solar and fuel cells, as well as in the construction industry for high-performance concrete, but also in medicine for drug delivery.