Neutrons are characterized by a low absorption in many engineering materials. At the same time the scattering cross section of light elements, such as hydrogen and deuterium, may be large. These properties make neutron scattering experiments performed under grazing incidence geometry an excellent tool for the study of solid–liquid interfaces. In this review we describe the basic concepts of neutron reflection and grazing incidence scattering experiments as well as experimental procedures and sample cells. The full power of the method is exemplified on a range of science areas, including polymers, bio- and ionic liquid lubricants, electrolytes as well as bio-membranes or magnetic liquids.