The current understanding of metal-ceramic interactions is presented based on wetting data obtained by the sessile drop technique. The nature of the bonding between metals and ceramics, with emphasis on ionocovalent oxide ceramics, is discussed using an electronic approach. Typical examples are given to illustrate the effect of oxygen on the wetting behaviour of a metal/ceramic system when it acts as a dissolved element in the liquid metal, and when it causes the formation of an oxide film on the metal surface and an oxide-like layer on the ceramic surface. The influence of alloying elements on the wetting properties is elucidated using a thermodynamic model. Following these discussions, the general behaviour of wetting and adhesion in metal/ceramic systems could thus be deduced.