Review of the past ten years of research and development in petroleum exploration throughout the world demonstrates the frequently changing pattern of emphasis and identifies the controlling factors and principles. Changing political and commercial attitudes, environmental controls, the pressures of population and energy demand, as well as availability, are among the parameters which will be reviewed. Against this background an attempt will be made to identify forward trends of research, not only in the technological fields of petroleum geology – geophysics, geochemistry, reservoir analysis, geotechnical engineering – but also in the environments that lie ahead and the pressures on commercial exploration.