Diamond has attractive properties as an advanced electronic material. Its combination of high mobility, breakdown, and thermal conductivity results in the largest Johnson's and Keyes' figures of merit by far. The realization of that potential is another matter. In this paper we review some of the reported achievements related to diamond as an electronic and sensor material. The state of heteroepitaxial films and polycrystalline diamond active electronics will be covered; negative electron affinity is briefly covered, and the piezoresistive effect in diamond and its relevance to sensing is described.