Volcanic gases contain species such as carbon dioxide, water and sulfur, but also small but significant concentrations of volatile metals and metalloids, such as copper, selenium, antimony. These elements may be toxic in large concentrations in our surface environment, but they are also nutrients and critical components of life. Magmatic systems and volcanoes play an important role in cycling these elements from the interior of our planet to the shallow crust, atmosphere and oceans. In this talk I will review the state of knowledge regarding the behaviour of these elements in silicate melts and exsolved fluids, based on measurements of volcanic gases, glasses, sulfides and fluid inclusions. I will discuss how the abundance and behaviour of these metals in volcanic and magmatic fluids differs between tectonic settings (and why) and the factors maximising the flux of these species to the surface environment. These studies help us to interrogate geological records such as ice cores, understand the formation of critical metal deposits, and understand better the links between metal cycling and life.